Ownership Summary

Top Holders	Shares Held	% O/S	Share Change	Filing Date
The Vanguard Group, Inc.	11,725,391	10.36	70,657	3/31/19
BlackRock Institutional Trust Company, N.A.	5,501,232	4.86	-152,561	3/31/19
State Street Global Advisors (US)	4,866,164	4.30	463,800	3/31/19
Jackson Square Partners, LLC	4,246,819	3.75	-143,939	3/31/19
Fidelity Management & Research Company	3,628,026	3.21	-112,073	3/31/19
JP Morgan Asset Management	2,885,560	2.55	970,929	3/31/19
Invesco Advisers, Inc.	2,386,318	2.11	-1,051,038	3/31/19
Citadel LLC	2,362,266	2.09	-1,427,517	3/31/19
T. Rowe Price Associates, Inc.	2,183,842	1.93	1,050,604	3/31/19
Ivy Investment Management Company	2,041,268	1.80	742,713	3/31/19

Fund	Shares Held	% O/S	Share Change	Filing Date
Vanguard Total Stock Market Index Fund	3,085,964	2.73	14,406	4/30/19
Vanguard Mid-Cap Index Fund	2,719,355	2.40	-5,616	4/30/19
Vanguard 500 Index Fund	2,235,728	1.98	44,563	4/30/19
SPDR S&P 500 ETF	1,290,452	1.14	23,732	4/30/19
Vanguard U.S. Growth Fund	1,289,225	1.14	--	3/31/19
Fidelity OTC Portfolio	1,141,700	1.01	--	3/31/19
US Bank Vanguard Institutional 500 Index Trust	1,067,219	0.94	-3,330	4/30/19
Invesco QQQ Trust	1,019,455	0.90	20,352	4/30/19
Statens Pensjonsfond Utland	1,014,358	0.90	91,649	12/31/18
JPMorgan Growth Advantage Fund	976,947	0.86	147,400	3/31/19

* Insider values reflect direct beneficial ownership.