Caruso Company had 500,000 shares of common stock issued and outstanding at December 31, 2007. On July 1, 2008 an additional 500,000 shares were issued for cash. Caruso also had stock options outstanding at the beginning and end of 2008 which allow the holders to purchase 150,000 shares of common stock at $20 per share. The average market price of Caruso's common stock was $25 during 2008. What is the number of shares that should be used in computing diluted earnings per share for the year ended December 31, 2008?