The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3-D SYS CORP DEL COM NEW COM 88554D205 866 95,115 SH   SOLE   95,115 0 0
3M COMPANY COM 88579y101 1,160 6,693 SH   SOLE   6,693 0 0
A. O. SMITH CORPORATION COM 831865209 490 10,380 SH   SOLE   10,380 0 0
AAC HOLDINGS INC COM 000307108 138 159,985 SH   SOLE   159,985 0 0
ABBOTT LABORATORIES COM 002824100 1,111 13,213 SH   SOLE   13,213 0 0
ABBVIE INC SHS COM 00287y109 652 8,972 SH   SOLE   8,972 0 0
ACCENTURE PLC F CLASS A COM g1151c101 327 1,770 SH   SOLE   1,770 0 0
AIR PRODUCTS & CHEMICALS, INC. COM 009158106 489 2,158 SH   SOLE   2,158 0 0
ALLEGION PLC COM G0176J109 2,724 24,643 SH   SOLE   24,643 0 0
ALLSTATE CORPORATION COM 020002101 2,950 29,014 SH   SOLE   29,014 0 0
ALPHABET INC CLASS C COM 02079K107 98,562 91,184 SH   SOLE   91,184 0 0
ALPHABET INC. CLASS A COM 02079k305 1,373 1,268 SH   SOLE   1,268 0 0
ALTRIA GROUP INC COM 02209s103 211 4,450 SH   SOLE   4,450 0 0
AMAZON.COM INC COM 023135106 123,285 65,105 SH   SOLE   65,105 0 0
AMERICAN TOWER CORP. COM 03027X100 124,740 610,126 SH   SOLE   610,126 0 0
AMGEN INC COM PV $0.0001 COM 031162100 923 5,006 SH   SOLE   5,006 0 0
ANSYS INC COM 03662Q105 200,385 978,345 SH   SOLE   978,345 0 0
APPLE INC COM 037833100 6,279 31,724 SH   SOLE   31,724 0 0
AUTOMATIC DATA PROC COM 053015103 2,209 13,361 SH   SOLE   13,361 0 0
BANK AMER CORP COM COM 060505104 241 8,322 SH   SOLE   8,322 0 0
BANK OF HAWAII CORP COM 062540109 244 2,942 SH   SOLE   2,942 0 0
BB&T CORPORATION COM 054937107 575 11,700 SH   SOLE   11,700 0 0
BEACON ROOFING SUPPLY INC COM 073685109 4,856 132,255 SH   SOLE   132,255 0 0
BECTON DICKINSON&CO COM 075887109 372 1,475 SH   SOLE   1,475 0 0
BERKLEY W R CORP COM 084423102 3,148 47,752 SH   SOLE   47,752 0 0
BERKSHIRE HATHAWAY INC DELAWA COM 084670108 2,865 9 SH   SOLE   9 0 0
BERKSHIRE HATHAWAY INC CL B COM 084670702 8,739 40,997 SH   SOLE   40,997 0 0
BIO-TECHNE CORP COM 09073M104 125,406 601,496 SH   SOLE   601,496 0 0
BLACK KNIGHT, INC. COM 09215C105 87,940 1,462,010 SH   SOLE   1,462,010 0 0
BLACKLINE, INC COM 09239B109 164,217 3,068,905 SH   SOLE   3,068,905 0 0
BRIGHT HORIZONS FAM SOL IN DEL COM 109194100 8,400 55,674 SH   SOLE   55,674 0 0
BROOKS AUTOMATION, INC COM 114340102 135,736 3,502,866 SH   SOLE   3,502,866 0 0
CALAVO GROWERS INC COM 128246105 5,833 60,294 SH   SOLE   60,294 0 0
CANADIAN NATL RY CO COM COM 136375102 1,850 20,000 SH   SOLE   20,000 0 0
CANTEL MEDICAL CORP COM 138098108 3,931 48,749 SH   SOLE   48,749 0 0
CAPITAL ONE FINL CORP COM COM 14040H105 2,468 27,200 SH   SOLE   27,200 0 0
CARMAX INC COM 143130102 131,822 1,518,156 SH   SOLE   1,518,156 0 0
CBRE GROUP INC COM 12504L109 85,236 1,661,526 SH   SOLE   1,661,526 0 0
CELGENE CORP COM 151020104 266 2,875 SH   SOLE   2,875 0 0
CHEVRON CORP COM 166764100 1,226 9,849 SH   SOLE   9,849 0 0
CHUBB LTD COM h1467j104 597 4,050 SH   SOLE   4,050 0 0
CIGNA CORP COM 125523100 311 1,974 SH   SOLE   1,974 0 0
CISCO SYSTEMS INC COM COM 17275r102 3,422 62,527 SH   SOLE   62,527 0 0
COCA COLA COM COM 191216100 2,017 39,613 SH   SOLE   39,613 0 0
COGENT COMMUNICATIONS COM 19239V302 9,276 156,275 SH   SOLE   156,275 0 0
COLGATE-PALMOLIVE CO COM 194162103 846 11,800 SH   SOLE   11,800 0 0
COMCAST CORP NEW CL A COM 20030n101 5,825 137,768 SH   SOLE   137,768 0 0
CONOCOPHILLIPS COM 20825c104 550 9,020 SH   SOLE   9,020 0 0
CONSOLIDATED EDISON INC COM COM 209115104 223 2,544 SH   SOLE   2,544 0 0
CONSTELLATION SOFTWARE INC. COM 21037x100 7,638 8,097 SH   SOLE   8,097 0 0
CORE LAB N.V. COM N22717107 17,250 329,948 SH   SOLE   329,948 0 0
COSTAR GROUP INC COM 22160N109 135,483 244,527 SH   SOLE   244,527 0 0
COUPA SOFTWARE COM 22266l106 3,066 24,213 SH   SOLE   24,213 0 0
CROWN CASTLE REIT INC SHS COM 22822v101 7,341 56,316 SH   SOLE   56,316 0 0
DANAHER CORP DEL COM COM 235851102 98,614 689,997 SH   SOLE   689,997 0 0
DELTA AIR LINES INC COM 247361702 227 4,000 SH   SOLE   4,000 0 0
DEXCOM INC COM 252131107 6,225 41,541 SH   SOLE   41,541 0 0
DISCOVER FINANCIAL SERVICES COM 254709108 4,856 62,583 SH   SOLE   62,583 0 0
DISNEY (WALT) CO COM STK COM 254687106 713 5,107 SH   SOLE   5,107 0 0
DOLLAR GENERAL COM 256677105 6,252 46,258 SH   SOLE   46,258 0 0
DOUGLAS DYNAMICS INC COM 25960R105 9,928 249,505 SH   SOLE   249,505 0 0
DUKE REALTY CORP REIT COM 264411505 346 10,950 SH   SOLE   10,950 0 0
EAST WEST BANCORP INC COM 27579r104 351 7,500 SH   SOLE   7,500 0 0
ECOLAB INC COM 278865100 236,023 1,195,415 SH   SOLE   1,195,415 0 0
EDWARDS LIFESCIENCES COM 28176e108 2,419 13,096 SH   SOLE   13,096 0 0
ELI LILLY & CO COM 532457108 801 7,229 SH   SOLE   7,229 0 0
EMERSON ELECTRIC CO COM 291011104 712 10,676 SH   SOLE   10,676 0 0
ENPHASE ENERGY INC COM 29355A107 292 16,000 SH   SOLE   16,000 0 0
ENTERPRISE PRDTS PRTN LPL P COM 293792107 1,239 42,911 SH   SOLE   42,911 0 0
ENVESTNET INC COM 29404K106 81,174 1,187,275 SH   SOLE   1,187,275 0 0
EQUITY RESIDENTIAL REIT COM 29476l107 291 3,838 SH   SOLE   3,838 0 0
EVENTBRITE INC COM 29975e109 2,536 156,542 SH   SOLE   156,542 0 0
EVERTEC INC COM 30040P103 3,620 110,696 SH   SOLE   110,696 0 0
EVO PAYMENT INC COM 26927e104 7,839 248,633 SH   SOLE   248,633 0 0
EXACT SCIENCES CORP COM COM 30063p105 354 3,000 SH   SOLE   3,000 0 0
EXPONENT INC COM 30214U102 3,875 66,199 SH   SOLE   66,199 0 0
EXXON MOBIL CORP COM COM 30231g102 2,011 26,247 SH   SOLE   26,247 0 0
FACEBOOK INC CLASS COM 30303m102 266 1,380 SH   SOLE   1,380 0 0
FASTENAL CO COM 311900104 144,164 4,423,569 SH   SOLE   4,423,569 0 0
FISERV INC COM 337738108 7,189 78,856 SH   SOLE   78,856 0 0
FORTINET INC COM COM 34959E109 789 10,263 SH   SOLE   10,263 0 0
FORTIVE CORPORATION COM 34959J108 204 2,508 SH   SOLE   2,508 0 0
GENERAL ELECTRIC COM 369604103 548 52,229 SH   SOLE   52,229 0 0
GENESEE AND WYOMING INC COM 371559105 68,188 681,885 SH   SOLE   681,885 0 0
GENUINE PARTS CO COM 372460105 329 3,179 SH   SOLE   3,179 0 0
GLU MOBILE INC COM 379890106 90 12,500 SH   SOLE   12,500 0 0
GUIDEWIRE SOFTWARE INC COM 40171V100 7,592 74,884 SH   SOLE   74,884 0 0
HAMILTON LANE INC COM 407497106 8,363 146,558 SH   SOLE   146,558 0 0
HCP INC COM 40414l109 1,510 47,211 SH   SOLE   47,211 0 0
HD SUPPLY HOLDINGS INC COM 40416M105 2,218 55,075 SH   SOLE   55,075 0 0
HEALTHCARE SERVICES GROUP INC COM 421906108 63,579 2,096,935 SH   SOLE   2,096,935 0 0
HEICO CORP NEW CL A COM 422806208 10,974 106,162 SH   SOLE   106,162 0 0
HELIOS TECHNOLOGIES ORD SHS COM 42328h109 4,276 92,146 SH   SOLE   92,146 0 0
HOME DEPOT INC COM 437076102 558 2,684 SH   SOLE   2,684 0 0
HONEYWELL INTL INC COM 438516106 3,664 20,986 SH   SOLE   20,986 0 0
IBM CORP COM 459200101 1,158 8,400 SH   SOLE   8,400 0 0
IDEXX LABORATORIES INC COM 45168D104 29,441 106,930 SH   SOLE   106,930 0 0
ILLINOIS TOOL WORKS COM 452308109 313 2,074 SH   SOLE   2,074 0 0
ILLUMINA INC COM 452327109 168,232 456,966 SH   SOLE   456,966 0 0
INTEL CORP COM 458140100 13,707 286,334 SH   SOLE   286,334 0 0
INTUITIVE SURGICAL INC COM 46120E602 135,438 258,198 SH   SOLE   258,198 0 0
JOHN BEAN TECHNOLOGIES COM 477839104 8,756 72,288 SH   SOLE   72,288 0 0
JOHNSON AND JOHNSON COM COM 478160104 14,714 105,643 SH   SOLE   105,643 0 0
JPMORGAN CHASE & CO COM 46625h100 4,333 38,754 SH   SOLE   38,754 0 0
KANSAS CITY SOUTHERN COM NEW COM 485170302 2,799 22,978 SH   SOLE   22,978 0 0
KEYON COMMUNI HOLD INC COM 493312201 0 16,667 SH   SOLE   16,667 0 0
KEYSIGHT TECHNOLOGIES INC COM 49338l103 2,466 27,456 SH   SOLE   27,456 0 0
KIMBERLY CLARK COM 494368103 362 2,713 SH   SOLE   2,713 0 0
LABORATORY CORP AMER HLDGS COM COM 50540R409 1,709 9,884 SH   SOLE   9,884 0 0
LEMAITRE VASCULAR COM 525558201 2,932 104,794 SH   SOLE   104,794 0 0
LINCOLN NTL CORP IND NPV COM 534187109 683 10,603 SH   SOLE   10,603 0 0
LITHIA MOTORS INC CL A COM 536797103 3,179 26,766 SH   SOLE   26,766 0 0
LITTELFUSE INC COM 537008104 3,722 21,037 SH   SOLE   21,037 0 0
LOWE'S COMPANIES INC COM 548661107 3,812 37,773 SH   SOLE   37,773 0 0
M & T BANK CORP COM 55261f104 785 4,613 SH   SOLE   4,613 0 0
MAGELLAN MIDSTREAM PRTNRS LP C COM 559080106 394 6,150 SH   SOLE   6,150 0 0
MARKEL CORP HLDG CO COM 570535104 172,187 158,028 SH   SOLE   158,028 0 0
MASTERCARD INC-CLASS A COM 57636Q104 120,212 454,437 SH   SOLE   454,437 0 0
MCCORMICK & CO INC COM NON VTG COM 579780206 1,946 12,555 SH   SOLE   12,555 0 0
MCDONALDS CORP COM COM 580135101 713 3,435 SH   SOLE   3,435 0 0
MERCK AND CO INC SHS COM 58933y105 4,384 52,282 SH   SOLE   52,282 0 0
MESA LABS INC COM 59064R109 6,361 26,033 SH   SOLE   26,033 0 0
MGP INGREDIENTS INC COM 55303J106 4,741 71,499 SH   SOLE   71,499 0 0
MICROSOFT CORP COM 594918104 14,635 109,251 SH   SOLE   109,251 0 0
MIDDLEBY CORP COM 596278101 6,524 48,078 SH   SOLE   48,078 0 0
MOHAWK INDS INC COM COM 608190104 1,555 10,545 SH   SOLE   10,545 0 0
MONRO INC COM 610236101 5,665 66,412 SH   SOLE   66,412 0 0
MOODYS CORP COM 615369105 159,100 814,603 SH   SOLE   814,603 0 0
NASPERS SPON ADR EACH REP 0.2 COM 631512209 327 6,750 SH   SOLE   6,750 0 0
NEOGEN CORP COM COM 640491106 770 12,400 SH   SOLE   12,400 0 0
NESTLE S A REP RG SH ADR COM 641069406 614 5,942 SH   SOLE   5,942 0 0
NORFOLK SOUTHERN CO COM 655844108 3,659 18,358 SH   SOLE   18,358 0 0
NOVANTA INC COM NPV COM 67000b104 7,925 84,041 SH   SOLE   84,041 0 0
NOVARTIS ADR COM 66987v109 483 5,285 SH   SOLE   5,285 0 0
NUTRIEN LTD COM 67077m108 1,964 36,740 SH   SOLE   36,740 0 0
O REILLY AUTOMOTIVE INC COM 67103H107 17,700 47,925 SH   SOLE   47,925 0 0
OKTA, INC COM 679295105 74,842 605,956 SH   SOLE   605,956 0 0
ORACLE CORPORATION COM 68389x105 294 5,165 SH   SOLE   5,165 0 0
ORTHOPEDIATRICS CORP COM 68752L100 10,287 263,781 SH   SOLE   263,781 0 0
PAYCHEX INC COM 704326107 3,936 47,830 SH   SOLE   47,830 0 0
PEPSICO INC COM 713448108 1,633 12,452 SH   SOLE   12,452 0 0
PFIZER INC COM 717081103 2,391 55,189 SH   SOLE   55,189 0 0
PHILIP MORRIS INTL COM 718172109 223 2,842 SH   SOLE   2,842 0 0
PHILLIPS 66 COM 718546104 203 2,170 SH   SOLE   2,170 0 0
PINNACLE WEST CAP CORP COM 723484101 282 3,000 SH   SOLE   3,000 0 0
PNC FINCL SERVICES GROUP COM 693475105 1,007 7,335 SH   SOLE   7,335 0 0
POOL CORPORATION COM 73278l105 592 3,098 SH   SOLE   3,098 0 0
PRICE T ROWE GROUP INC COM 74144T108 12,885 117,449 SH   SOLE   117,449 0 0
PROCTER & GAMBLE CO COM 742718109 16,096 146,792 SH   SOLE   146,792 0 0
PROS HOLDINGS INC COM 74346Y103 157,711 2,493,068 SH   SOLE   2,493,068 0 0
QUALCOMM INC COM 747525103 25,753 338,542 SH   SOLE   338,542 0 0
QUALYS INC COM COM 74758t303 54,611 627,134 SH   SOLE   627,134 0 0
RED HAT INC COM 756577102 69,204 368,578 SH   SOLE   368,578 0 0
ROPER TECHNOLOGIES INC COM 776696106 199,462 544,592 SH   SOLE   544,592 0 0
RPM INTERNATIONAL INC COM 749685103 255 4,175 SH   SOLE   4,175 0 0
S & P GLOBAL INC COM 78409V104 123,228 540,971 SH   SOLE   540,971 0 0
SALESFORCE.COM INC COM 79466L302 228 1,500 SH   SOLE   1,500 0 0
SBA COMMUNICATIONS CORP CL A COM 78410G104 74,508 331,384 SH   SOLE   331,384 0 0
SCHLUMBERGER LTD COM 806857108 2,620 65,917 SH   SOLE   65,917 0 0
SEI INVESTMENTS CO COM 784117103 13,216 235,573 SH   SOLE   235,573 0 0
SERVICE CORP INTL COM 817565104 304 6,500 SH   SOLE   6,500 0 0
SITEONE LANDSCAPE SUPPLY, INC. COM 82982L103 8,367 120,740 SH   SOLE   120,740 0 0
STANLEY BLACK & DECK COM 854502101 291 2,010 SH   SOLE   2,010 0 0
STERIS PLC COM G8473t100 946 6,351 SH   SOLE   6,351 0 0
STRYKER CORP COM 863667101 212 1,030 SH   SOLE   1,030 0 0
TE CONNECTIVITY LTD F COM h84989104 2,296 23,970 SH   SOLE   23,970 0 0
TELADOC INC COM 87918A105 6,303 94,907 SH   SOLE   94,907 0 0
TELEFLEX INC COM COM 879369106 87,526 264,308 SH   SOLE   264,308 0 0
THE BOEING CO COM 097023105 322 884 SH   SOLE   884 0 0
THE DESCARTES SYSTEMS GROUP IN COM 249906108 2,472 66,893 SH   SOLE   66,893 0 0
THERMO FISHER SCNTFC COM 883556102 63,013 214,565 SH   SOLE   214,565 0 0
TRACTOR SUPPLY COMP COM 892356106 1,372 12,609 SH   SOLE   12,609 0 0
TRANSDIGM GROUP INC COM 893641100 132,161 273,173 SH   SOLE   273,173 0 0
TRANSUNION COM 89400j107 21,467 292,022 SH   SOLE   292,022 0 0
TREX COMPANY, INC. COM 89531P105 3,876 54,052 SH   SOLE   54,052 0 0
TRIMBLE INC COM 896239100 81,378 1,803,989 SH   SOLE   1,803,989 0 0
TRUPANION, INC. COM 898202106 4,149 114,832 SH   SOLE   114,832 0 0
TYLER TECHNOLOGIES INC COM 902252105 165,916 768,059 SH   SOLE   768,059 0 0
U S BANCORP COM 902973304 1,406 26,831 SH   SOLE   26,831 0 0
UNION PACIFIC CORP COM 907818108 326 1,930 SH   SOLE   1,930 0 0
UNITED PARCEL SERVICE INC CL B COM 911312106 280 2,716 SH   SOLE   2,716 0 0
UNITED TECHNOLOGIES CORP. COM 913017109 1,132 8,697 SH   SOLE   8,697 0 0
UNITEDHEALTH GRP INC COM 91324p102 1,719 7,043 SH   SOLE   7,043 0 0
VAPOTHERM INC COM 922107107 4,950 215,200 SH   SOLE   215,200 0 0
VENTAS INC REIT COM 92276f100 1,389 20,324 SH   SOLE   20,324 0 0
VERISK ANALYTICS INC COM 92345Y106 214,645 1,465,552 SH   SOLE   1,465,552 0 0
VERIZON COMMUNICATIONS INC COM 92343v104 748 13,091 SH   SOLE   13,091 0 0
VISA INC CL A COM 92826C839 217,613 1,253,890 SH   SOLE   1,253,890 0 0
VULCAN MATERIALS CO COM 929160109 151,115 1,100,540 SH   SOLE   1,100,540 0 0
W.P. CAREY INC. REIT COM 92936u109 414 5,095 SH   SOLE   5,095 0 0
WALMART STORES COM 931142103 491 4,441 SH   SOLE   4,441 0 0
WASTE CONNECTIONS INC COM 94106B101 157,263 1,645,355 SH   SOLE   1,645,355 0 0
WATSCO INC COM 942622200 15,090 92,277 SH   SOLE   92,277 0 0
WAYFAIR COM 94419L101 7,240 49,588 SH   SOLE   49,588 0 0
WD-40 COMPANY COM 929236107 2,620 16,472 SH   SOLE   16,472 0 0
WESTINGHOUSE AIR BRAKE TECHNOL COM 929740108 1,918 26,725 SH   SOLE   26,725 0 0
WORKDAY INC COM 98138H101 1,142 5,553 SH   SOLE   5,553 0 0
WSFS FINANCIAL CORP COM 929328102 3,136 75,926 SH   SOLE   75,926 0 0
BLACKROCK ENHANCED EQT DIV TR ETFS 09251A104 89 10,000 SH   SOLE   10,000 0 0
ISHARES CORE S&P 500 ETF ETFS 464287200 1,159 3,931 SH   SOLE   3,931 0 0
ISHARES CORE S&P MID CAP ETF ETFS 464287507 1,133 5,834 SH   SOLE   5,834 0 0
ISHARES CORE S&P SMALL CAP ETF ETFS 464287804 493 6,303 SH   SOLE   6,303 0 0
ISHARES MSCI EAFE ETF ETFS 464287465 889 13,523 SH   SOLE   13,523 0 0
ISHARES RUSSELL 2000 GROWTH IN ETFS 464287648 201 1,000 SH   SOLE   1,000 0 0
ISHARES TR MSCI EMG MKT ETF ETFS 464287234 215 4,999 SH   SOLE   4,999 0 0
SPDR GOLD TRUST ETFS 78463v107 204 1,533 SH   SOLE   1,533 0 0
VANGUARD DIVIDEND APPREC ETFS 921908844 1,288 11,184 SH   SOLE   11,184 0 0
VANGUARD FTSE ALL WORLD EX US ETFS 922042775 3,390 66,478 SH   SOLE   66,478 0 0
VANGUARD FTSE EMERGING MARK ET ETFS 922042858 972 22,843 SH   SOLE   22,843 0 0
VANGUARD HIGH DIVIDEND YIELD E ETFS 921946406 686 7,851 SH   SOLE   7,851 0 0
VANGUARD REIT ETF ETFS 922908553 1,106 12,655 SH   SOLE   12,655 0 0
VANGUARD S&P 500 ETF ETFS 922908363 5,145 19,114 SH   SOLE   19,114 0 0
VANGUARD TOTAL STK MKT ETF ETFS 922908769 392 2,615 SH   SOLE   2,615 0 0
WISDOMTREE TR INDIA ERNGS FD ETFS 97717W422 235 9,000 SH   SOLE   9,000 0 0