8. Share-based Payment Expense  |  continued Fair values The weighted average fair value assigned to the 3-year euro-denominated options granted in 2012 under the 2010 share option scheme was €3.43 (2011: €4.03).  The fair values of these options were determined using the following assumptions: Other than the assumptions listed above, no other features of option grants were factored into the determination of fair value. No relevant modifications were  effected to either the 2010 share option scheme or the previously approved 2000 share option scheme during the course of 2012. The Group operates a Performance Share Plan which was approved by shareholders in May 2006. The expense of €14 million (2011: €12 million) reported in the Consolidated Income Statement has been arrived at through applying a Monte Carlo simulation  technique to model the combination of market-based and non-market-based performance conditions in the Plan. The fair value of the shares awarded was determined using a Monte Carlo simulation technique taking account of peer group total shareholder return, volatilities  and correlations, together with the following assumptions: *  In February 2012, 226,617 (16.6% of the initial award net of lapses) of the shares awarded under the Performance Share Plan in 2009 vested and accordingly were released to the  participants of the scheme. 2012 2011 Weighted average exercise price €15.19 €16.38 Risk-free interest rate 0.80% 2.68% Expected dividend payments over the expected life  €3.25 €3.25 Expected volatility 33.8% 32.9% Expected life in years 5 5 Share price at  date of award Period to  earliest  release date Number of Shares Fair  value Initial award Cumulative lapses/releases  to date* Net outstanding Granted in 2009 €17.00 3 years 1,658,000 (1,658,000)  -  €8.29 Granted in 2010 €18.51 3 years 1,459,750 (210,500) 1,249,250 €10.01 Granted in 2011 €16.52 3 years 1,684,250 (88,000) 1,596,250 €9.72 Granted in 2012 €15.63 3 years  2,079,000   -   2,079,000 €7.77 2012 2011 Risk-free interest rate (%)  0.33   2.08  Expected volatility (%)  35.4   38.6  The expected volatility was determined using a historical sample of 37 month-end CRH share prices. CRH 89 Performance Share Plan The expected volatility was determined using a historical sample of 61 month-end CRH share prices. Share options are granted at market value at the date of  grant. The expected lives of the options are based on historical data and are therefore not necessarily indicative of exercise patterns that may materialise.