c) Share Options Under our current share option plan, 10 million Class B shares have been set aside for the grant of share options to  full-time employees, of which 7.7 million remain available for grant. The exercise price for each option is the closing  price for our Class B shares on the last trading day before the date of grant. Our share options are settled through the  issuance of Class B shares. During the year ended December 31, 2012, we granted 1,524,821 Class B share options at market prices to employees.  These share options have a weighted average exercise price of $39.24, vest in equal amounts over three years and  have a term of 10 years. The weighted average fair value of Class B share options granted in the year was estimated at $12.15 per option  (2011 - $19.44) at the grant date based on the Black-Scholes option-pricing model using the following assumptions: The expected volatility is based on a statistical analysis of daily share prices over the expected option life. Outstanding share options are as follows: 2012 2011 Weighted average exercise price  $ 39.24 $ 58.71 Dividend yield 2.04% 1.02% Risk-free interest rate  1.38% 2.63% Expected option life  4.2 years 4.2 years Expected volatility 43% 41% Forfeiture rate 2.50% 2.13% 2012 2011 Weighted Weighted  Average Average  Shares Exercise Shares Exercise  (in 000’s)  Price  (in 000’s)  Price Outstanding at beginning of year 5,768 $ 30.51 5,228 $ 24.79 Granted 1,525 39.24 910 58.71 Exercised (188) 8.27 (245) 15.75 Forfeited (172) 43.23 (122) 24.75 Expired (80) 39.21 (3) 43.74 Outstanding at end of year  6,853 $ 32.65 5,768 $ 30.51 Vested and exercisable at end of year  4,471 $ 27.00 3,334 $ 27.56 The average share price during the year was $33.74 (2011 - $45.69). Generations 115