For the years ended December 31, 2016, 2015 and 2014, our total stock-based compensation expense, which includes reversals of expense for certain forfeited or cancelled awards, was approximately $278,000, $2.4 million and $1.6 million, respectively. We have not recorded any income tax benefit related to stock-based compensation for the years ended December 31, 2016, 2015 and 2014.

A summary of the status of our stock options as of December 31, 2016, and changes during the year then ended, is presented below: 

The weighted average grant-date fair value of options granted in 2016, 2015, and 2014 was $0.53, $1.67 and $1.56, respectively. During 2016, 50,000 stock options with an aggregate intrinsic value of $23,000 were exercised in exchange for issuance of 50,000 shares of our common stock, resulting in gross proceeds of $13,500. During 2015, 146,625 stock options with an aggregate intrinsic value of $144,000 were exercised in exchange for issuance of 124,238 shares of our common stock, resulting in gross proceeds of $66,000. During 2014, 468,000 stock options with an aggregate intrinsic value of $582,000 were exercised in exchange for issuance of 299,360 shares of our common stock, resulting in gross proceeds of $70,000. In 2016, 2015, and 2014, the aggregate fair value of stock options vested during the year was $3,000, $277,000 and $4,000, respectively.

A summary of the status of our unvested restricted stock as of December 31, 2016, and changes during the year then ended, is presented below:

During 2016, 2015 and 2014, 66,000, 333,250 and 216,250 shares, respectively, of restricted stock vested with aggregate vesting date fair values of $63,000, $511,000 and $387,000, respectively.

In February 2016, 100,000 shares of restricted stock held by an executive officer with an aggregate fair value of $96,000 were forfeited in connection with his separation from employment. During 2016, 66,000 shares of restricted stock held by non-employee directors with an aggregate fair value of $63,000 vested as scheduled according to the terms of the restricted stock agreements. Also during 2016, 106,000 shares of restricted stock held by non-employee directors with an aggregate fair value of $118,000 were forfeited as a result of their departures from the Board.

During 2015, 120,000 shares of restricted stock held by non-employee directors with an aggregate fair value of $193,000 vested as scheduled according to the terms of the restricted stock agreements. Also during 2015, 193,250 shares of restricted stock held by employees with an aggregate fair value of $286,000 vested as scheduled according to the terms of the restricted stock agreements. During 2015, 27,000 shares of restricted stock held by employees with an aggregate fair value of $50,000 were forfeited in connection with their separation from employment. In April 2015, 20,000 shares of restricted stock held by an executive officer with an aggregate fair value of $32,000 vested upon reaching a milestone as defined by the terms of the restricted stock agreement. In May 2015, 20,000 shares of restricted stock held by an executive officer with an aggregate fair value of $25,000 were forfeited in connection with his separation from employment. In July 2015, 61,000 shares of restricted stock held by non-employee directors with an aggregate fair value of $107,000 were forfeited as a result of their departures from the Board.

During 2014, 61,250 shares of restricted stock held by non-employee directors with an aggregate fair value of $111,000 vested as scheduled according to the terms of the restricted stock agreements. Also during 2014, 40,000 shares of restricted stock held by executive officers with an aggregate fair value of $52,000 vested upon reaching certain milestones as defined by the terms of the restricted stock agreements. In March 2014, 100,000 shares of restricted stock with an aggregate fair value of $205,000 vested as scheduled according to the terms of the restricted stock agreement. In May 2014, 175,000 shares of restricted stock held by our former CEO with an aggregate fair value of $278,000 were forfeited in connection with his separation from employment. In September 2014, 125,000 shares of restricted stock held by our former CEO with an aggregate fair value of $166,000 were forfeited in connection with termination of his Consulting Agreement. In December 2014, 15,000 shares of restricted stock held by our former CEO with an aggregate fair value of $19,000 vested as scheduled in accordance with the terms of the restricted stock agreement.

During 2015 and 2014, we paid minimum tax withholdings related to stock options exercised and restricted stock vested of $24,000 and $131,000, respectively. No such tax withholdings were paid related to stock options exercised or restricted stock vested during 2016. As of December 31, 2016, there was approximately $223,000 of total unrecognized compensation cost related to stock option and restricted stock awards, which we expect to recognize over remaining weighted average vesting terms of 1.2 years. See Note 1(e).