Share Option Awards No time-based share option awards were granted for the years ended December 31, 2018 or 2017. The fair value of each time-based option award is estimated on the date of grant using the Black-Scholes option-pricing model. The estimated fair value of the share options is amortized over the vesting period using the straight-line method. The assumptions used within the option-pricing model for the time-based awards are as follows: 2016 -% 30.36%-33.01% 1.20%-1.48% 6.00 years Dividend yield Expected share price volatility Risk-free interest rate Expected term Expected volatility was determined based on the historical share prices in our industry. The risk-free rate was based on U.S. Treasury zero coupon issues with a remaining term equal to the expected option term at grant date. The expected term was calculated under the simplified method. The performance-based options awarded to our President and Chief Executive Officer in August 2015 are subject to performance conditions such that the number of awards that ultimately vest depends on the adjusted earnings per share ("Adjusted EPS") and adjusted return on invested capital ("Adjusted ROIC") achieved by the Company during the performance period compared to targets established at the award date. Although the terms of the performance-based awards provide the compensation committee with the discretion to make certain adjustments to the performance calculation, it was determined that a mutual understanding of the key terms and conditions of the awards has been ascertained. In 2018, the grant date was therefore established for performance-based awards granted in prior years. The fair value of each performance-based option award is estimated on the date of grant using the Black-Scholes option-pricing model. The estimated fair value of the share options is amortized over the requisite service period using the straight-line method. The assumptions used within the option-pricing model for the performance-based awards are as follows: 2018 -% 31.50%-32.20% 2.48-2.58% 3.72-4.22 years Dividend yield Expected share price volatility Risk-free interest rate Expected term 2017 -% 25.97% 1.81% 4.20 years 2016 -% 25.97%-30.21% 1.01%-1.93% 4.38-5.13 years Expected volatility was determined based on the historical share prices in our industry. The risk-free rate was based on U.S. Treasury zero coupon issues with a remaining term equal to the expected option term at grant date. The expected term was calculated under the simplified method. F-23