ORBIT GAR ANT DRILLING INC NOTES TO THE CONSOLID A TED FINANCIAL ST A TEMENTS Continued Amounts as at March 31 2008 and for the nine and three months ended March 31 2008 and for the six and three months ended March 31 2007 are unaudited 11 SHARE C APIT AL Continued The companys calculations of the fair value of the 1017000 options granted during the 9 months ended June 30 2007 were made using the BlackScholes optionpricing model with weighted average assumptions as follows Riskfree interest rate 410 Expected life 5 years Expected volatility 4 6 Expected dividend yield 0 F air value of options granted 046 The companys calculations of the fair value of the 38500 options granted during the 9 months ended March 31 2008 were made u sing the BlackScholes optionpricing model with weighted average assumptions as follows Riskfree interest rate 410 Expected life 5 years Expected volatility 4 4 Expected dividend yield 0 F air value of options granted 066 Earnings per share Diluted earnings per common share were calculated based on net earnings divided by the average number of common shares outstanding taking into account the dilution effect of stock options using the treasury stock method March 31 March 31 March 31 March 31 June 30 2008 2007 2008 2007 2007 3 months 3 months 9 months 6 months 9 months unaudited unaudited unaudited unaudited Earnings per share basic Net earnings available to common shareholders 2823920 637313 7960492 659999 1899093 A verage basic number of common shares outstanding 24776536 18982584 24771591 14392582 17760450 Earnings per share basic 011 003 032 005 011 Earnings per share diluted Net earnings available to common shareholders 2823920 637313 7960492 659999 1899093 A verage basic number of common shares outstanding 24776536 18982584 24771591 14392582 17760450 A djustment to average number of common shares Stock options 716550 942000 859800 942000 813600 A verage diluted number of common shares outstanding 25493086 19924584 25631391 15334582 18574050 Earnings per share diluted 011 003 031 004 010 F21