Directors’ share options

Hi, I have a question regarding Directors’ share options.

GBL granted 50,000 share options to each of its six directors. Each option gives the right to buy one ordinary share in GBL for $1.50 at the vesting date of 31 March 2015. In order for the options to vest, GBL’s profit after tax must rise by 50% over the three-year period from 1 April 2012 to 31 March 2015 and the director must still hold office at 31 March 2015.

The fair value of a share option at 1 April 2012 was estimated to be $0.80. GBL anticipates at each year end that only one director will leave prior to the vesting date. It is confident that GBL will achieve the required profit after tax target by the vesting date. As at 31 March 2015, the profit after tax target is eventually not achieved.

The amount recognised as an expense/(reversal of expense) for each of the three years is calculated as follows:

2013: 50,000 options x 3 directors x $0.8 x 1/3
2014: 50,000 options x 3 directors x $0.8 x 2/3
2015: 50,000 options x 3 directors x $0.8 x 2/3

I think the numbers of directors should be 5 in 2013 and 4 in 2014, but not 3 for all 3 years. Is my understanding correct? Thanks.