Effective January 2014, the Company has its own defined contribution plan (the “Contribution Plan”) under Section 401(k) of the Internal Revenue Code for all eligible employees who have completed one month of service. The Contribution Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended. Participants may contribute up to 100% of their annual eligible compensation, subject to IRS limitations and ERISA. The Company makes matching contributions of 50% on the first 8% of employee contributions per pay period up to a maximum of $4,000. Employees become vested in these Company contributions 33% upon one year of service, 66% upon two years of service and 100% upon three years of service. Company matching contributions aggregated $920,000, $733,000 and $628,000 for the years ended December 31, 2018, 2017 and 2016, respectively, which is included in selling, general and administrative expense in the consolidated statements of net and comprehensive income.