-80.22% is the change from 91 to 18
Calculation steps:
[( 18 - 91 ) ÷ 91] x 100 = -80.22%
Formula
Percentage change = [(18 - 91) / 91] x 100
Subtract the new number by the original number
18 - 91 = -73
-73 ÷ 91 = -0.8021978021978022
-0.8021978021978022 x 100 = -80.22%