Closing Market Price and NAV History

Date	Market Price1	Net Asset Value2	Bid/Ask Midpoint	Volume1	Net Assets2
5/31/2013	$45.82	$45.82	$45.83	106,030	$1,021,701,078
5/30/2013	$46.04	$46.01	$46.02	178,090	$1,026,024,916
5/29/2013	$45.47	$45.44	$45.47	93,923	$1,013,282,733
5/28/2013	$45.79	$45.79	$45.79	72,753	$1,021,111,868
5/24/2013	$45.49	$45.49	$45.49	118,715	$1,014,379,243
5/23/2013	$45.68	$45.72	$45.73	116,621	$1,019,475,136
5/22/2013	$45.71	$45.75	$45.79	162,653	$1,020,330,987
5/21/2013	$46.65	$46.62	$46.64	99,060	$1,039,544,580
5/20/2013	$46.76	$46.73	$46.75	160,553	$1,025,630,516
5/17/2013	$46.50	$46.51	$46.52	109,157	$1,020,799,201
5/16/2013	$46.10	$46.10	$46.11	156,521	$1,011,818,137
5/15/2013	$46.43	$46.41	$46.43	141,770	$1,018,766,268
5/14/2013	$46.13	$46.10	$46.12	186,179	$1,011,967,306
5/13/2013	$45.30	$45.27	$45.29	185,262	$989,254,412
5/10/2013	$45.08	$45.07	$45.07	100,421	$984,729,911
5/9/2013	$44.49	$44.49	$44.50	117,230	$972,184,889
5/8/2013	$44.74	$44.72	$44.72	103,230	$977,024,015
5/7/2013	$44.47	$44.45	$44.46	109,748	$971,337,315
5/6/2013	$44.37	$44.37	$44.39	186,571	$960,526,860
5/3/2013	$44.35	$44.36	$44.37	89,859	$956,050,216
5/2/2013	$43.86	$43.84	$43.86	119,730	$944,767,506
5/1/2013	$43.14	$43.11	$43.13	114,888	$928,976,824