Exhibit A

TRANSACTIONS BY REPORTING PERSONS IN LAST 60 DAYS

Beneficial Ownership	Purchase or Sale	Quantity	Transaction Date	Price per Share (including commission)	How Effected
Relational Investors Mid-Cap Fund I, L.P.	Purchase	55,822	9/26/2011	26.01	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	2,941	9/26/2011	26.08	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	52,378	9/26/2011	26.01	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	2,759	9/26/2011	26.08	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	63,108	9/27/2011	27.02	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	59,215	9/27/2011	27.02	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	44,737	9/28/2011	26.68	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	41,977	9/28/2011	26.68	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	61,909	9/29/2011	26.85	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	24,741	9/29/2011	26.83	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	58,091	9/29/2011	26.85	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	23,214	9/29/2011	26.83	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	51,591	9/30/2011	26.84	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	48,409	9/30/2011	26.84	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	92,349	10/3/2011	26.49	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	60,408	10/3/2011	26.49	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	75,447	10/4/2011	26.19	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	49,353	10/4/2011	26.19	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	10,860	10/7/2011	27.51	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	7,103	10/7/2011	27.51	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	83,245	11/10/2011	27.53	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	42,858	11/10/2011	27.53	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	12,543	11/11/2011	27.71	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	6,457	11/11/2011	27.71	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	79,282	11/14/2011	27.20	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	44,726	11/14/2011	27.34	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	40,818	11/14/2011	27.20	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	23,027	11/14/2011	27.34	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	23,034	11/15/2011	27.90	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	11,859	11/15/2011	27.90	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	125,806	11/16/2011	28.74	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	39,188	11/16/2011	28.80	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	31,557	11/16/2011	28.77	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	64,772	11/16/2011	28.74	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	20,176	11/16/2011	28.80	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	16,247	11/16/2011	28.77	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	117,639	11/17/2011	29.02	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	36,681	11/17/2011	29.11	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	26,636	11/17/2011	29.24	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	60,567	11/17/2011	29.02	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	18,884	11/17/2011	29.11	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	13,713	11/17/2011	29.24	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	49,898	11/18/2011	29.53	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	25,690	11/18/2011	29.53	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	94,224	11/21/2011	29.15	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	33,007	11/21/2011	28.93	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	48,511	11/21/2011	29.15	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	16,993	11/21/2011	28.93	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	18,484	11/22/2011	29.66	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	43,990	11/22/2011	29.44	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	9,516	11/22/2011	29.66	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	22,648	11/22/2011	29.44	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	98,759	11/23/2011	29.45	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	50,847	11/23/2011	29.45	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	33,006	11/25/2011	29.17	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	16,994	11/25/2011	29.17	Open Market