-92.4% is the change from 171 to 13
Calculation steps:
[( 13 - 171 ) ÷ 171] x 100 = -92.4%
Formula
Percentage change = [(13 - 171) / 171] x 100
Subtract the new number by the original number
13 - 171 = -158
-158 ÷ 171 = -0.9239766081871345
-0.9239766081871345 x 100 = -92.4%