Table of Contents COHERENT, INC. AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued) 13. EMPLOYEE STOCK AWARD AND BENEFIT PLANS (continued) The following table summarizes the activity of our time-based and performance restricted stock units for fiscal 2019, 2018 and 2017 (in thousands, except per share amounts): (1) Service-based restricted stock units vested during each fiscal year. Performance-based restricted stock units included at 100% of target goal. Under the terms of the awards, the recipient may earn between 0% and 200% of the award. Restricted Stock Units are converted into the right to receive common stock upon vesting; prior to issuance, the Company permits the employee holders to satisfy their tax withholding requirements by net settlement, whereby the Company withholds a portion of the shares to cover the applicable taxes based on the fair market value of the Company's stock at the vesting date. The number of shares withheld to cover tax payments was 120,000 in fiscal 2019, 131,000 in fiscal 2018 and 131,000 in fiscal 2017; tax payments made were $15.2 million, $36.3 million and $15.7 million, respectively. 14. DEFINED BENEFIT PLANS  As a result of the Rofin acquisition, we have assumed all assets and liabilities of Rofin's defined benefit plans for the Rofin-Sinar Laser, GmbH ("RSL") and Rofin-Sinar Inc. ("RS Inc.") employees. The U.S. plan began in fiscal 1995 and is partially funded. Any new employees hired after January 1, 2007, are not eligible for the RS Inc. pension plan. As is the customary practice with German companies, the German pension plan is unfunded. Any new employees hired after 2000 are not eligible for the RSL pension plan. The measurement date of these pension plans is September 30. For these pension plans, actuarial gains and losses are deferred into OCI and amortized over future periods. Effective January 1, 2012, the RS Inc. defined benefit plan was amended to exclude highly compensated employees, as defined by the Internal Revenue Service, from receiving future years of service under the RS Inc. defined benefit plan. A non-qualified defined benefit plan was created to replace the benefits lost by the employees that were otherwise excluded from the qualified defined benefit plan. Effective August 31, 2018 both the RS Inc. plans were amended to freeze all future compensation benefit accruals. In addition, we have defined benefit plans in South Korea, Japan, Spain and Italy, covering all full-time employees with at least one year of service, and a defined benefit plan in Germany covering two individuals. As is the customary practice with European and Asian companies, the plans are unfunded, with the exception of the Spanish plan which is partially funded. We have elected to recognize all actuarial gains and losses on these plans immediately, as incurred. The measurement date of these defined benefit plans is September 30. 104 Time Based Restricted Stock Units Performance Restricted Stock Units Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Nonvested stock at October 1, 2016 459 $ 66.47 169 $ 74.10 Granted 186 131.54 115 163.17 Vested  (1) (229 ) 66.02 (104 ) 77.10 Forfeited (17) 84.79 (4) 70.57 Nonvested stock at September 30, 2017 399 $ 118.83 176 $ 105.34 Granted 99 254.20 78 315.05 Vested (1) (213 ) 88.45 (95 ) 70.57 Forfeited (6) 119.66 — — Nonvested stock at September 29, 2018 279 $ 155.24 159 $ 155.76 Granted 195 128.25 105 117.43 Vested (1) (169 ) 127.90 (131 ) 74.48 Forfeited (10) 170.97 — — Nonvested stock at September 28, 2019 295 $ 152.47 133 $ 184.26