Closing Market Price and NAV History

Date	Market Price1	Net Asset Value2	Bid/Ask Midpoint	Volume1	Net Assets2
4/30/2015	$54.34	$54.34	$54.37	58,264	$937,311,937
4/29/2015	$54.95	$54.90	$54.94	108,874	$947,074,687
4/28/2015	$55.19	$55.14	$55.17	114,474	$951,159,877
4/27/2015	$54.83	$54.82	$54.79	76,216	$945,621,119
4/24/2015	$55.31	$55.26	$55.24	65,366	$953,222,071
4/23/2015	$55.57	$55.51	$55.56	48,465	$957,578,629
4/22/2015	$55.26	$55.21	$55.21	40,485	$952,356,903
4/21/2015	$55.10	$55.06	$55.08	53,134	$949,801,873
4/20/2015	$55.24	$55.20	$55.18	93,666	$952,126,458
4/17/2015	$54.81	$54.76	$54.78	83,502	$944,539,366
4/16/2015	$55.51	$55.47	$55.43	65,541	$956,933,300
4/15/2015	$55.77	$55.72	$55.74	96,802	$961,256,165
4/14/2015	$55.25	$55.22	$55.23	58,796	$949,715,667
4/13/2015	$55.09	$55.06	$55.08	52,456	$946,962,656
4/10/2015	$55.31	$55.26	$55.25	77,944	$950,492,666
4/9/2015	$55.15	$55.10	$55.13	78,571	$947,719,066
4/8/2015	$55.03	$54.97	$55.01	200,292	$937,218,122
4/7/2015	$54.75	$54.76	$54.75	63,315	$1,062,251,111
4/6/2015	$55.15	$55.14	$55.16	167,298	$934,684,390
4/2/2015	$54.64	$54.60	$54.60	59,388	$925,391,204
4/1/2015	$54.39	$54.39	$54.37	198,497	$916,394,188