Ownership Profile

Top Holders

Holder Shares Held % O/S Share Change Filing Date
BlackRock Institutional Trust Company, N.A. 3,370,977 11.58 114,325 12/31/17
The Vanguard Group, Inc. 2,937,748 10.09 61,591 12/31/17
Mairs and Power, Inc. 1,916,574 6.58 -36,620 12/31/17
Kayne Anderson Rudnick Investment Management, LLC 1,675,359 5.75 17,615 12/31/17
Impax Asset Management Ltd. 1,460,883 5.02 25,192 3/31/18
Dimensional Fund Advisors, L.P. 1,118,953 3.84 624 12/31/17
T. Rowe Price Associates, Inc. 1,041,957 3.58 -103,315 12/31/17
State Street Global Advisors (US) 741,502 2.55 27,423 12/31/17
UBS Asset Management (Americas), Inc. 654,358 2.25 93,983 12/31/17
Goldman Sachs Asset Management (US) 568,282 1.95 -54,875 12/31/17

Top Holders: Mutual Funds

Fund Shares Held % O/S Share Change Filing Date
iShares Core S&P Small-Cap ETF 1,423,697 4.89 64,116 3/31/18
Mairs and Power Growth Fund 1,065,000 3.66 -5,000 12/31/17
Vanguard Total Stock Market Index Fund 678,158 2.33 12,793 2/28/18
Vanguard Small-Cap Index Fund 660,329 2.27 -14,391 3/31/18
iShares Russell 2000 ETF 564,469 1.94 -492 3/31/18
Statens Pensjonsfond Utland 519,504 1.78 321,406 12/31/17
Goldman Sachs Small/Mid-Cap Growth Fund 515,696 1.77 -9,661 3/31/18
T. Rowe Price Small Cap Value Fund 502,409 1.73 -200,900 3/31/18
Stichting Pensioenfonds Zorg en Welzijn 459,099 1.58 459,099 12/31/16
BNP Paribas AQUA P 447,425 1.54 -- 1/31/18

* Insider values reflect direct beneficial ownership.