2.2% is the change from 911 to 931
Calculation steps:
[( 931 - 911 ) ÷ 911] x 100 = 2.2%
Formula
Percentage change = [(931 - 911) / 911] x 100
Subtract the new number by the original number
931 - 911 = 20
20 ÷ 911 = 0.021953896816684963
0.021953896816684963 x 100 = 2.2%