-7.02% is the change from 171 to 159
Calculation steps:
[( 159 - 171 ) ÷ 171] x 100 = -7.02%
Formula
Percentage change = [(159 - 171) / 171] x 100
Subtract the new number by the original number
159 - 171 = -12
-12 ÷ 171 = -0.07017543859649122
-0.07017543859649122 x 100 = -7.02%