-88.3% is the change from 171 to 20
Calculation steps:
[( 20 - 171 ) ÷ 171] x 100 = -88.3%
Formula
Percentage change = [(20 - 171) / 171] x 100
Subtract the new number by the original number
20 - 171 = -151
-151 ÷ 171 = -0.8830409356725146
-0.8830409356725146 x 100 = -88.3%