| Top Institutional Holders |
|---|
| Holder | Shares | % Out | Value* | Reported |
|---|
| Vanguard Group, Inc. (The) | 1,696,625 | 4.73 | 2,969,093 | Mar 31, 2013 | | Granahan Investment Management Inc. | 1,386,600 | 3.87 | 2,426,550 | Mar 31, 2013 | | Dimensional Fund Advisors LP | 1,382,733 | 3.86 | 2,419,782 | Mar 31, 2013 | | BlackRock Institutional Trust Company, N.A. | 1,157,175 | 3.23 | 2,025,056 | Mar 31, 2013 | | Wells Fargo & Company | 837,534 | 2.34 | 1,465,684 | Mar 31, 2013 | | Bridgeway Capital Management, Inc. | 632,800 | 1.76 | 1,107,400 | Mar 31, 2013 | | CALPERS (California-Public Employees Retirement System) | 393,000 | 1.10 | 687,750 | Mar 31, 2013 | | Arrowstreet Capital, Limited Partnership | 297,732 | 0.83 | 521,031 | Mar 31, 2013 | | Bank of America Corporation | 242,711 | 0.68 | 424,744 | Mar 31, 2013 | | Northern Trust Corporation | 232,721 | 0.65 | 407,261 | Mar 31, 2013 |
|
| Holder | Shares | % Out | Value* | Reported |
|---|
| Vanguard Explorer Fund, Inc. | 979,200 | 2.73 | 2,957,184 | Jan 31, 2013 | | Vanguard Small-Cap Index Fund | 591,183 | 1.65 | 1,897,697 | Dec 31, 2012 | | Vanguard Total Stock Market Index Fund | 499,937 | 1.39 | 1,604,797 | Dec 31, 2012 | | Bridgeway Funds Inc-Ultra Small Company Fund | 423,900 | 1.18 | 741,825 | Mar 31, 2013 | | Vanguard Extended Market Index Fund | 404,981 | 1.13 | 1,299,989 | Dec 31, 2012 | | Wells Fargo Advantage Small/Mid Cap Value Fd | 380,600 | 1.06 | 666,050 | Mar 31, 2013 | | Vanguard Variable Insurance Fund-Small Company Growth | 292,400 | 0.82 | 511,700 | Mar 31, 2013 | | Blackrock Funds-All Cap Energy & Resources Portfolio | 286,500 | 0.80 | 919,665 | Dec 31, 2012 | | Vanguard Small-Cap Growth Index Fund | 269,242 | 0.75 | 864,266 | Dec 31, 2012 | | Blackrock Funds-Energy & Resources Portfolio | 245,700 | 0.69 | 788,697 | Dec 31, 2012 |
|
View Transactions for Insiders & Institutional Holders Value shown is computed using the security's price on the report date given. Currency in USD. |