On January 1, 2016, Wade Corporation had 24,000 shares of common stock outstanding. On April 1, it reacquired 2,400 shares; on July 1, it issued 10,800 shares; on October 1, it issued another 9,600 shares; and on December 1, it reacquired 900 shares. What was the weighted average number of common shares outstanding for 2016