-12.28% is the change from 171 to 150
Calculation steps:
[( 150 - 171 ) ÷ 171] x 100 = -12.28%
Formula
Percentage change = [(150 - 171) / 171] x 100
Subtract the new number by the original number
150 - 171 = -21
-21 ÷ 171 = -0.12280701754385964
-0.12280701754385964 x 100 = -12.28%