This excerpt taken from the ELN 6-K filed Aug 28, 2009.
We grant share options to certain employees, directors and consultants under our 2006 Long-Term Incentive Plan (2006 LTIP). The options are granted at fixed exercise prices equal to the market value of our shares on the date of grant. The terms and conditions of the share option plans and option activities are disclosed in our 2008 Annual Report. Additional grants of share options on similar terms were made to employees and directors during the first half of 2009.
The fair value of services received in return for share options granted to employees is measured by reference to the fair value of share options granted. The fair value of share options is calculated using a binomial option-pricing model, and the fair value of options issued under our employee equity purchase plans, which are described further below, is calculated using the Black-Scholes option-pricing model, taking into consideration the relevant terms and conditions.
The estimated weighted-average grant date fair values of share options awarded during the first half of 2009 and 2008 were $5.47 and $13.96 per share, respectively. The fair value was estimated using the binomial option-pricing model with the following weighted-average assumptions: