Ownership Summary

Top Holders	Shares Held	% O/S	Share Change	Filing Date
The Vanguard Group, Inc.	11,654,734	10.30	262,916	12/31/18
BlackRock Institutional Trust Company, N.A.	5,653,793	5.00	266,130	12/31/18
State Street Global Advisors (US)	4,402,364	3.89	280,272	12/31/18
Jackson Square Partners, LLC	4,390,758	3.88	399,682	12/31/18
Citadel LLC	3,789,783	3.35	1,870,476	12/31/18
Fidelity Management & Research Company	3,740,099	3.31	277,285	12/31/18
Invesco Advisers, Inc.	3,437,356	3.04	924,761	12/31/18
Allianz Global Investors U.S. LLC	2,281,245	2.02	132,837	12/31/18
JP Morgan Asset Management	1,914,631	1.69	97,854	12/31/18
Macquarie Investment Management	1,783,505	1.58	-150,599	12/31/18

Fund	Shares Held	% O/S	Share Change	Filing Date
Vanguard Total Stock Market Index Fund	3,048,511	2.69	9,826	2/28/19
Vanguard Mid-Cap Index Fund	2,708,149	2.39	-16,762	2/28/19
Vanguard 500 Index Fund	2,173,846	1.92	14,785	2/28/19
Vanguard U.S. Growth Fund	1,289,225	1.14	175,431	12/31/18
SPDR S&P 500 ETF	1,262,504	1.12	-28,288	2/28/19
US Bank Vanguard Institutional 500 Index Trust	1,082,531	0.96	3,363	2/28/19
Invesco QQQ Trust	994,836	0.88	-9,415	2/28/19
Invesco American Franchise Fund	930,594	0.82	--	1/31/19
Statens Pensjonsfond Utland	922,709	0.82	255,479	12/31/17
Delaware U.S. Growth Fund	865,553	0.76	13,065	12/31/18

* Insider values reflect direct beneficial ownership.