Table:
|  | Years Ended December 31, |  |
| --- | --- | --- |
|  | 2018 | 2017 |
| Expected life (years) | 5.6 | 5.6 |
| Risk-free interest rate | 2.7% | 1.9% |
| Expected volatility | 26.4% | 29.4% |
| Expected dividend yield | — | — |
Paragraphs:
The fair value of options granted in the respective fiscal years are estimated on the date of grant using the Black-Scholes optionpricing model, acceptable under ASC 718, with the following weighted average assumptions:
Expected volatilities are based on the Company’s historical common stock volatility, derived from historical stock price data for periods commensurate with the options’ expected life. The expected life of options granted represents the period of time options are expected to be outstanding, based primarily on historical employee option exercise behavior. The risk-free interest rate is based on the implied yield currently available on U.S. Treasury zero coupon bonds issued with a term equal to the expected life at the date of grant of the options. The expected dividend yield is zero, as the Company has historically paid no dividends and does not anticipate dividends to be paid in the future.
Question:
What was the change in risk-free interest rate between 2017 and 2018?
Answer: 2.7%-1.9% = 0.8