97  The following assumptions were used for the fair value calculations:  D) Development of plans  E) Employee benefit trust  The Group established an employee benefit trust (the “Trust”). The Trust purchases shares in the Group for the benefit of employees under the Group’s  share option scheme. At 31 December 2012 the Trust held 2,679,768 shares (2011: 1,267,322). The weighted average share price at the date of exercise of options was €16.30 and €14.04 in the years ended 31 December 2012 and 2011 respectively.  Liabilities from share option exercises to employees were nil at 31 December 2012 (2011: US$135,000).  The following table summarises information on stock options outstanding (including stock options granted under the LTIP and the EIP) at 31 December  2012:  Stock option plan activity (including stock options granted under the LTIP and the EIP) for the years ended 31 December 2012 and 2011 was as follows:  2012  2011  Options Weighted average  exercise price  €  Options Weighted average  exercise price € Outstanding at beginning of year  6,160,579 5.48  6,098,193 2.88 Granted  1,557,339 11.22  2,975,730 6.45 Exercised  (1,584,866) 1.93  (2,727,709) 0.60 Forfeited  (254,227) 9.07  (185,635) 7.35 Outstanding at end of year 5,878,825 7.83  6,160,579 5.48 Options exercisable at year end  2,976,684 4.46  3,532,169 1.90 Options outstanding  Options exercisable  Range of Exercise Prices  Number  outstanding at 31  December 2012 Weighted average  remaining  contractual life (in years) Weighted average  exercise price  €  Number exercisable  at 31 December 2012 Weighted average  exercise price € €0.11 - 2.99  2,331,018 3.2 0.56  1,820,661 0.64 €3.00 - 8.00  513,433 3.7 6.63  361,450 6.52 €8.00 - 15.50  3,034,374 5.7 13.62  794,573 12.27 €0.11 - 15.50  5,878,825 4.5 7.83  2,976,684 4.46 Grant in 2012 $_{Share price at grant date}$  €16,43 $_{Exercise price}$  €0.12 Expected volatility 38% Risk free interest rate 0.2% Assumed level of vesting regarding the performance conditions 50% $_{Option lifetime }$  6 Years 21. Share-based payments continued 