On May 16, 2019, the Company’s shareholders approved the Company’s Amended and Restated 2008 Incentive Compensation Plan (the “Amended and Restated 2008 Incentive Plan”). The amendments, among other things, increased the number of shares of common stock reserved for delivery under the under the Amended and Restated 2008 Incentive Plan from 19,500,000 shares to 27,775,000 shares, as well as extended the expiration date to ten years from the effective date of approval. The Amended and Restated 2008 Incentive Plan provides for grants of stock options, stock appreciation rights, restricted stock, deferred stock, and other stock-related awards and performance awards that may be settled in cash, stock or other property.

Under the Amended and Restated 2008 Incentive Plan, options to purchase shares of common stock may be granted at a price not less than the fair market value of the shares on the date of grant. The options must be exercised within 10 years from the date of grant and generally become exercisable on a pro rata basis over a three-year period from the date of grant. The Company issues new shares of its common stock upon exercise of its stock options. Restricted stock awards generally vest over periods of three years upon the fulfillment of specified service-based conditions and in certain instances performance-based conditions. Deferred stock awards generally vest upon the satisfaction of specified performance-based conditions and service-based conditions. The Company recognizes compensation expense related to its restricted stock and deferred stock awards ratably over the corresponding vesting periods. During the six months ended June 30, 2019, the Company granted 1,100,913 shares of restricted stock to its employees and

non-employee

directors under the Amended and Restated 2008 Incentive Plan. At June 30, 2019, the Company had 8.2 million shares available for future grants and awards under its Amended and Restated 2008 Incentive Plan.

Under the Company’s 1996

Non-Qualified

Employee Stock Purchase Plan, as amended (the “ESPP”), employees are permitted to purchase the Company’s common stock at 85% of market value on January 1st, April 1st, July 1st and October 1st of each year. Under the Company’s 2015

Non-Qualified

Stock Purchase Plan (the “SPP”), certain eligible

non-employee

service providers are permitted to purchase the Company’s common stock at 90% of market value on January 1st, April 1st, July 1st and October 1st of each year.

Each of the ESPP and the SPP provide for the issuance of an aggregate of 2.6 million shares of the Company’s common stock less the number of shares of common stock purchased under the other plan. The Company recognizes stock-based compensation expense for the discount received by participating employees and

non-employee

service providers. During the six months ended June 30, 2019, 0.3 million shares in aggregate were issued under the ESPP and SPP. At June 30, 2019, the Company had approximately 1.3 million shares in aggregate reserved for issuance under the ESPP and SPP.

During the three and six months ended June 30, 2019 and 2018, the Company recognized stock-based compensation expense of $10.0 million and $21.0 million, and $10.3 million and $20.0 million, respectively.