Exhibit A

Transactions by Reporting Persons in the 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	17,451	11/22/2011	5.62	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	197,484	11/22/2011	5.65	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	9,059	11/22/2011	5.62	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	102,516	11/22/2011	5.65	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	230,398	11/23/2011	5.56	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	493,710	11/23/2011	5.53	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	119,602	11/23/2011	5.56	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	256,290	11/23/2011	5.53	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	65,828	11/25/2011	5.53	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	34,172	11/25/2011	5.53	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	65,828	11/28/2011	5.65	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	394,967	11/28/2011	5.59	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	34,172	11/28/2011	5.65	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	205,033	11/28/2011	5.59	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	278,774	11/29/2011	5.53	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	144,716	11/29/2011	5.53	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	196,425	1/4/2012	5.50	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	147,695	1/4/2012	5.49	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	235,710	1/4/2012	5.50	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	53,575	1/4/2012	5.50	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	40,284	1/4/2012	5.49	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	64,290	1/4/2012	5.50	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	262,745	1/5/2012	5.58	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	82,749	1/5/2012	5.68	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	71,664	1/5/2012	5.58	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	22,569	1/5/2012	5.68	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	241,445	1/6/2012	5.74	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	65,855	1/6/2012	5.74	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	78,570	1/9/2012	5.97	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	401,334	1/9/2012	5.95	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	21,430	1/9/2012	5.97	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	109,466	1/9/2012	5.95	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	711,842	1/10/2012	6.02	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	235,710	1/10/2012	6.01	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	194,158	1/10/2012	6.02	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	64,290	1/10/2012	6.01	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	109,134	1/11/2012	6.00	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	87,213	1/11/2012	6.03	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	29,766	1/11/2012	6.00	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	23,787	1/11/2012	6.03	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	63,013	1/12/2012	6.01	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	17,187	1/12/2012	6.01	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	78,570	1/13/2012	5.97	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	314,278	1/13/2012	5.89	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Purchase	682,056	1/13/2012	5.89	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	21,430	1/13/2012	5.97	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	85,722	1/13/2012	5.89	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Purchase	186,038	1/13/2012	5.89	Open Market