CONSOLIDATED WATER CO. LTD. NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Expressed in United States dollars) 10. Earnings per share Basic earnings per share is calculated by dividing the net profit attributable to stockholders by the weighted average number of ordinary shares of common stock in issue during the year, excluding the average number of ordinary shares of common stock purchased by the Company and held as treasury shares (see Note 8). The net income and weighted average number of ordinary shares of common stock and potential ordinary shares figures used in the determination of the basic and diluted earnings per ordinary share of common stock are summarized as follows: 2000 1999 1998 Net income used in determination of diluted earnings per ordinary share of common stock $ 2,404,820 $ 1,569,717 $ 1,451,933 Less: Dividends paid on non-vested redeemable preferred stock  ( 8,040) ( 8,025) ( 6,998) Earnings attributable to vested redeemable preferred stock  ( 6,180) ( 461) ( 3,336) Net income available to holders of ordinary shares of common stock in the determination of basic earnings per ordinary share of common stock $2,390,600 $1,561,231 $1,441,599 Weighted average number of ordinary shares  of common stock in the determination of basic  earnings per ordinary share of common stock 3,532,501 3,044,293 3,055,845 Plus: Weighted average number of redeemable  preferred stock outstanding during the year 37,145 44,707 40,231 Potential dilutive effect of unexercised options 41,147 48,954 56,596 Potential dilutive effect of unexercised warrants 5,478 50,094 38,911 Weighted average number of shares used for determining diluted earnings per ordinary share of common stock 3,616,271 3,188,048 3,191,583 As detailed in Note 16, 30,000 options were granted to an investment company on December 15, 1998 with an exercise price of $7.88. In addition, 85,259 options were granted to executive directors and senior management of the Company on December 31, 2000 with an exercise price of $7.10. At December 31, 2000, these options were antidilutive for the purpose of determining diluted earnings per share.