(1) Includes 3,963 shares of Common Stock representing a beneficial interest in shares of Common Stock of the Aon Common Stock Fund of the Aon Supplemental Savings Plan attributable to Mr. Ryan. Also includes 232,765 shares of Common Stock that Mr. Ryan has the right to acquire pursuant to presently exercisable employee stock options, or stock options that will become exercisable or stock awards that will vest within 60 days following February 25, 2011. (2) Shares power to vote with Shirley W. Ryan. (3) Shares power to dispose with Shirley W. Ryan. (4) Shares power to vote with Patrick G. Ryan. (5) Shares power to dispose with Patrick G. Ryan. Since February 25, 2010, the filing persons have effected the following transactions in Aon Common Stock: From February 25, 2010 through December 31, 2010, the filing persons acquired beneficial ownership of 2,437 shares of Aon Common Stock through a distribution from the Aon Employee Stock Ownership Plan. In addition, the filing persons sold an aggregate of 3,894,964 shares of Aon Common Stock pursuant to open market transactions. These sales occurred at prices ranging from $37.04 to $46.05. From January 1, 2011 through February 25, 2011, the filing persons acquired beneficial ownership of 14,830 shares of Aon Common Stock through the settlement of restricted stock unit awards previously granted to Mr. Ryan under various Aon equity incentive plans. In addition, the filing persons sold an aggregate of 610,000 shares of Aon Common Stock pursuant to open market transactions. These sales occurred at prices ranging from $45.45 to $52.61. No transactions, other than as described above, in Aon Common Stock were effected by any of the persons filing this statement within the past sixty days. As a result of the foregoing transactions and the increase in the number of shares of Aon Common Stock outstanding, as of February 25, 2011, the filing persons ceased to be the beneficial owners of more than 5% of |