Table:
0
A
B
C
D
1
Employee and Director Options
2
For the Years Ended December 31,
3
2019
2018
2017
4
Expected life (in years)
7.85
7.64
7.01
5
Volatility
30.00%
32.37%
35.00%
6
Risk free interest rate
1.90%
3.10%
2.14%
7
Dividend yield
0.76%
0.61%
0.50%
8
Weighted-average grant date fair value
$17.12
$21.03
$21.11
9
Stock price volatility range:
10
Low
30.00%
31.72%
28.19%
11
High
38.17%
36.73%
35.00%

Questions and formulas:
Question: What was the change in volatility between 2018 and 2019?
Formula: B5-C5
Formula2: B5-C5
Level: Calculation
Question: What was the change in risk free interest rate between 2017 and 2018?
Formula: C6-D6
Formula2: C6-D6
Level: Calculation
Question: What was the percentage change in the weighted-average grant date fair value between 2018 and 2019?
Formula: (B8-C8)/C8
Formula2: (B8-C8)/C8
Level: Calculation