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 LLC	Sale	1,081	4/21/2015	$	83.44	Open Market
Relational Investors LLC	Sale	414	4/21/2015	$	83.45	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	1,561	4/21/2015	$	83.44	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	3,172	4/21/2015	$	83.44	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	1,813	4/21/2015	$	83.45	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,056	4/21/2015	$	83.44	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	1,939	4/21/2015	$	83.45	Open Market
Relational Investors LLC	Sale	3,587	4/21/2015	$	83.44	Open Market
Relational Investors LLC	Sale	1,374	4/21/2015	$	83.45	Open Market
Relational Coast Partners, L.P.	Sale	1,174	4/21/2015	$	83.44	Open Market
Relational Coast Partners, L.P.	Sale	449	4/21/2015	$	83.45	Open Market
Relational Fund Partners, L.P.	Sale	74	4/21/2015	$	83.44	Open Market
Relational Fund Partners, L.P.	Sale	28	4/21/2015	$	83.45	Open Market
RH Fund 1, L.P.	Sale	527	4/21/2015	$	83.44	Open Market
RH Fund 1, L.P.	Sale	202	4/21/2015	$	83.45	Open Market
Relational Investors XV, L.P.	Sale	786	4/21/2015	$	83.44	Open Market
Relational Investors XV, L.P.	Sale	301	4/21/2015	$	83.45	Open Market
Relational Investors XVI, L.P.	Sale	389	4/21/2015	$	83.44	Open Market
Relational Investors XVI, L.P.	Sale	149	4/21/2015	$	83.45	Open Market
Relational Investors XX, L.P.	Sale	708	4/21/2015	$	83.44	Open Market
Relational Investors XX, L.P.	Sale	271	4/21/2015	$	83.45	Open Market
Relational Investors XXIII, L.P.	Sale	1,004	4/21/2015	$	83.44	Open Market
Relational Investors XXIII, L.P.	Sale	384	4/21/2015	$	83.45	Open Market
Relational Investors IX, L.P.	Sale	952	4/21/2015	$	83.44	Open Market
Relational Investors IX, L.P.	Sale	408	4/21/2015	$	83.44	Open Market
Relational Investors IX, L.P.	Sale	521	4/21/2015	$	83.45	Open Market
Relational Investors LLC	Sale	3,109	4/21/2015	$	83.44	Open Market
Relational Investors LLC	Sale	1,191	4/21/2015	$	83.45	Open Market
Relational Investors XXIV, L.P.	Sale	20	4/21/2015	$	83.44	Open Market
Relational Investors XXIV, L.P.	Sale	8	4/21/2015	$	83.45	Open Market
Relational Investors LLC	Sale	1,520	4/22/2015	$	82.82	Open Market
Relational Investors LLC	Sale	1,144	4/22/2015	$	82.85	Open Market
Relational Investors LLC	Sale	1,373	4/22/2015	$	82.62	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	2,492	4/22/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	4,164	4/22/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	5,012	4/22/2015	$	82.85	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	987	4/22/2015	$	82.62	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	5,027	4/22/2015	$	82.62	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	7,106	4/22/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,351	4/22/2015	$	82.85	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	6,419	4/22/2015	$	82.62	Open Market
Relational Investors LLC	Sale	5,045	4/22/2015	$	82.82	Open Market
Relational Investors LLC	Sale	1,307	4/22/2015	$	82.85	Open Market
Relational Investors LLC	Sale	2,492	4/22/2015	$	82.85	Open Market
Relational Investors LLC	Sale	4,559	4/22/2015	$	82.62	Open Market
Relational Coast Partners, L.P.	Sale	1,038	4/22/2015	$	82.82	Open Market
Relational Coast Partners, L.P.	Sale	613	4/22/2015	$	82.82	Open Market

Relational Coast Partners, L.P.	Sale	1,243	4/22/2015	$	82.85	Open Market
Relational Coast Partners, L.P.	Sale	1,492	4/22/2015	$	82.62	Open Market
Relational Fund Partners, L.P.	Sale	105	4/22/2015	$	82.82	Open Market
Relational Fund Partners, L.P.	Sale	79	4/22/2015	$	82.85	Open Market
Relational Fund Partners, L.P.	Sale	95	4/22/2015	$	82.62	Open Market
RH Fund 1, L.P.	Sale	742	4/22/2015	$	82.82	Open Market
RH Fund 1, L.P.	Sale	559	4/22/2015	$	82.85	Open Market
RH Fund 1, L.P.	Sale	671	4/22/2015	$	82.62	Open Market
Relational Investors XV, L.P.	Sale	156	4/22/2015	$	82.82	Open Market
Relational Investors XV, L.P.	Sale	950	4/22/2015	$	82.82	Open Market
Relational Investors XV, L.P.	Sale	832	4/22/2015	$	82.85	Open Market
Relational Investors XV, L.P.	Sale	999	4/22/2015	$	82.62	Open Market
Relational Investors XVI, L.P.	Sale	548	4/22/2015	$	82.82	Open Market
Relational Investors XVI, L.P.	Sale	412	4/22/2015	$	82.85	Open Market
Relational Investors XVI, L.P.	Sale	495	4/22/2015	$	82.62	Open Market
Relational Investors XX, L.P.	Sale	996	4/22/2015	$	82.82	Open Market
Relational Investors XX, L.P.	Sale	750	4/22/2015	$	82.85	Open Market
Relational Investors XX, L.P.	Sale	900	4/22/2015	$	82.62	Open Market
Relational Investors XXIII, L.P.	Sale	1,412	4/22/2015	$	82.82	Open Market
Relational Investors XXIII, L.P.	Sale	1,063	4/22/2015	$	82.85	Open Market
Relational Investors XXIII, L.P.	Sale	1,276	4/22/2015	$	82.62	Open Market
Relational Investors IX, L.P.	Sale	1,913	4/22/2015	$	82.82	Open Market
Relational Investors IX, L.P.	Sale	1,009	4/22/2015	$	82.85	Open Market
Relational Investors IX, L.P.	Sale	432	4/22/2015	$	82.85	Open Market
Relational Investors IX, L.P.	Sale	330	4/22/2015	$	82.62	Open Market
Relational Investors IX, L.P.	Sale	1,399	4/22/2015	$	82.62	Open Market
Relational Investors LLC	Sale	4,374	4/22/2015	$	82.82	Open Market
Relational Investors LLC	Sale	3,293	4/22/2015	$	82.85	Open Market
Relational Investors LLC	Sale	3,952	4/22/2015	$	82.62	Open Market
Relational Investors XXIV, L.P.	Sale	29	4/22/2015	$	82.82	Open Market
Relational Investors XXIV, L.P.	Sale	22	4/22/2015	$	82.85	Open Market
Relational Investors XXIV, L.P.	Sale	26	4/22/2015	$	82.62	Open Market
Relational Investors LLC	Sale	1,145	4/23/2015	$	83.25	Open Market
Relational Investors LLC	Sale	3,301	4/23/2015	$	83.23	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	5,012	4/23/2015	$	83.25	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	14,450	4/23/2015	$	83.23	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,349	4/23/2015	$	83.25	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	10,715	4/23/2015	$	83.23	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	4,696	4/23/2015	$	83.23	Open Market
Relational Investors LLC	Sale	3,799	4/23/2015	$	83.25	Open Market
Relational Investors LLC	Sale	10,952	4/23/2015	$	83.23	Open Market
Relational Coast Partners, L.P.	Sale	1,243	4/23/2015	$	83.25	Open Market
Relational Coast Partners, L.P.	Sale	3,585	4/23/2015	$	83.23	Open Market
Relational Fund Partners, L.P.	Sale	31	4/23/2015	$	83.25	Open Market
Relational Fund Partners, L.P.	Sale	48	4/23/2015	$	83.25	Open Market
Relational Fund Partners, L.P.	Sale	33	4/23/2015	$	83.23	Open Market
Relational Fund Partners, L.P.	Sale	137	4/23/2015	$	83.23	Open Market

Relational Fund Partners, L.P.	Sale	58	4/23/2015	$	83.23	Open Market
RH Fund 1, L.P.	Sale	559	4/23/2015	$	83.25	Open Market
RH Fund 1, L.P.	Sale	916	4/23/2015	$	83.23	Open Market
RH Fund 1, L.P.	Sale	696	4/23/2015	$	83.23	Open Market
Relational Investors XV, L.P.	Sale	832	4/23/2015	$	83.25	Open Market
Relational Investors XV, L.P.	Sale	2,401	4/23/2015	$	83.23	Open Market
Relational Investors XVI, L.P.	Sale	413	4/23/2015	$	83.25	Open Market
Relational Investors XVI, L.P.	Sale	1,183	4/23/2015	$	83.23	Open Market
Relational Investors XVI, L.P.	Sale	7	4/23/2015	$	83.23	Open Market
Relational Investors XX, L.P.	Sale	750	4/23/2015	$	83.25	Open Market
Relational Investors XX, L.P.	Sale	2,162	4/23/2015	$	83.23	Open Market
Relational Investors XXIII, L.P.	Sale	1,063	4/23/2015	$	83.25	Open Market
Relational Investors XXIII, L.P.	Sale	3,066	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	710	4/23/2015	$	83.25	Open Market
Relational Investors IX, L.P.	Sale	626	4/23/2015	$	83.25	Open Market
Relational Investors IX, L.P.	Sale	105	4/23/2015	$	83.25	Open Market
Relational Investors IX, L.P.	Sale	164	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	45	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	20	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	2,536	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	143	4/23/2015	$	83.23	Open Market
Relational Investors IX, L.P.	Sale	1,246	4/23/2015	$	83.23	Open Market
Relational Investors LLC	Sale	3,293	4/23/2015	$	83.25	Open Market
Relational Investors LLC	Sale	9,494	4/23/2015	$	83.23	Open Market
Relational Investors XXIV, L.P.	Sale	22	4/23/2015	$	83.25	Open Market
Relational Investors XXIV, L.P.	Sale	30	4/23/2015	$	83.23	Open Market
Relational Investors XXIV, L.P.	Sale	34	4/23/2015	$	83.23	Open Market
Relational Investors LLC	Sale	1,163	4/24/2015	$	82.93	Open Market
Relational Investors LLC	Sale	931	4/24/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	5,092	4/24/2015	$	82.93	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	4,078	4/24/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,434	4/24/2015	$	82.93	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	2,137	4/24/2015	$	82.82	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	2,216	4/24/2015	$	82.82	Open Market
Relational Investors LLC	Sale	3,860	4/24/2015	$	82.93	Open Market
Relational Investors LLC	Sale	3,091	4/24/2015	$	82.82	Open Market
Relational Coast Partners, L.P.	Sale	1,263	4/24/2015	$	82.93	Open Market
Relational Coast Partners, L.P.	Sale	1,012	4/24/2015	$	82.82	Open Market
Relational Fund Partners, L.P.	Sale	80	4/24/2015	$	82.93	Open Market
Relational Fund Partners, L.P.	Sale	49	4/24/2015	$	82.82	Open Market
Relational Fund Partners, L.P.	Sale	15	4/24/2015	$	82.82	Open Market
RH Fund 1, L.P.	Sale	568	4/24/2015	$	82.93	Open Market
RH Fund 1, L.P.	Sale	455	4/24/2015	$	82.82	Open Market
Relational Investors XV, L.P.	Sale	846	4/24/2015	$	82.93	Open Market
Relational Investors XV, L.P.	Sale	677	4/24/2015	$	82.82	Open Market
Relational Investors XVI, L.P.	Sale	419	4/24/2015	$	82.93	Open Market
Relational Investors XVI, L.P.	Sale	336	4/24/2015	$	82.82	Open Market

Relational Investors XX, L.P.	Sale	762	4/24/2015	$	82.93	Open Market
Relational Investors XX, L.P.	Sale	610	4/24/2015	$	82.82	Open Market
Relational Investors XXIII, L.P.	Sale	1,081	4/24/2015	$	82.93	Open Market
Relational Investors XXIII, L.P.	Sale	865	4/24/2015	$	82.82	Open Market
Relational Investors IX, L.P.	Sale	386	4/24/2015	$	82.93	Open Market
Relational Investors IX, L.P.	Sale	639	4/24/2015	$	82.93	Open Market
Relational Investors IX, L.P.	Sale	122	4/24/2015	$	82.93	Open Market
Relational Investors IX, L.P.	Sale	317	4/24/2015	$	82.93	Open Market
Relational Investors IX, L.P.	Sale	1,172	4/24/2015	$	82.82	Open Market
Relational Investors LLC	Sale	3,346	4/24/2015	$	82.93	Open Market
Relational Investors LLC	Sale	2,679	4/24/2015	$	82.82	Open Market
Relational Investors XXIV, L.P.	Sale	22	4/24/2015	$	82.93	Open Market
Relational Investors XXIV, L.P.	Sale	18	4/24/2015	$	82.82	Open Market
Relational Investors LLC	Sale	1,146	4/27/2015	$	82.87	Open Market
Relational Investors LLC	Sale	3,187	4/27/2015	$	83.14	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	5,014	4/27/2015	$	82.87	Open Market
Relational Investors Mid-Cap Fund I, L.P.	Sale	13,946	4/27/2015	$	83.14	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	5,338	4/27/2015	$	82.87	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	562	4/27/2015	$	83.14	Open Market
Relational Investors Mid-Cap Fund II, L.P.	Sale	14,288	4/27/2015	$	83.14	Open Market
Relational Investors LLC	Sale	3,800	4/27/2015	$	82.87	Open Market
Relational Investors LLC	Sale	10,571	4/27/2015	$	83.14	Open Market
Relational Coast Partners, L.P.	Sale	1,245	4/27/2015	$	82.87	Open Market
Relational Coast Partners, L.P.	Sale	3,461	4/27/2015	$	83.14	Open Market
Relational Fund Partners, L.P.	Sale	80	4/27/2015	$	82.87	Open Market
Relational Fund Partners, L.P.	Sale	223	4/27/2015	$	83.14	Open Market
RH Fund 1, L.P.	Sale	559	4/27/2015	$	82.87	Open Market
RH Fund 1, L.P.	Sale	1,557	4/27/2015	$	83.14	Open Market
Relational Investors XV, L.P.	Sale	833	4/27/2015	$	82.87	Open Market
Relational Investors XV, L.P.	Sale	2,320	4/27/2015	$	83.14	Open Market
Relational Investors XVI, L.P.	Sale	413	4/27/2015	$	82.87	Open Market
Relational Investors XVI, L.P.	Sale	1,151	4/27/2015	$	83.14	Open Market
Relational Investors XX, L.P.	Sale	750	4/27/2015	$	82.87	Open Market
Relational Investors XX, L.P.	Sale	2,089	4/27/2015	$	83.14	Open Market
Relational Investors XXIII, L.P.	Sale	1,064	4/27/2015	$	82.87	Open Market
Relational Investors XXIII, L.P.	Sale	2,961	4/27/2015	$	83.14	Open Market
Relational Investors IX, L.P.	Sale	1,442	4/27/2015	$	82.87	Open Market
Relational Investors IX, L.P.	Sale	2,807	4/27/2015	$	83.14	Open Market
Relational Investors IX, L.P.	Sale	1,203	4/27/2015	$	83.14	Open Market
Relational Investors LLC	Sale	3,294	4/27/2015	$	82.87	Open Market
Relational Investors LLC	Sale	9,164	4/27/2015	$	83.14	Open Market
Relational Investors XXIV, L.P.	Sale	22	4/27/2015	$	82.87	Open Market
Relational Investors XXIV, L.P.	Sale	64	4/27/2015	$	83.14	Open Market