At March 31, 2016, there were warrants outstanding to purchase 1,967,375 shares of common stock with a weighted average exercise price of $0.97 and a weighted average remaining life of 3.1 years. During the three months ended March 31, 2016, a warrant to purchase 1,875 shares of common stock was exercised on a cashless basis resulting in the issuance of 693 shares. During the three months ended March 31, 2015, warrants to purchase 62,129 shares of common stock were exercised.  There were no warrants issued or cancelled during the three months ended March 31, 2016 and 2015.