-7.6% is the change from 171 to 158
Calculation steps:
[( 158 - 171 ) ÷ 171] x 100 = -7.6%
Formula
Percentage change = [(158 - 171) / 171] x 100
Subtract the new number by the original number
158 - 171 = -13
-13 ÷ 171 = -0.07602339181286549
-0.07602339181286549 x 100 = -7.6%