-91.28% is the change from 172 to 15
Calculation steps:
[( 15 - 172 ) ÷ 172] x 100 = -91.28%
Formula
Percentage change = [(15 - 172) / 172] x 100
Subtract the new number by the original number
15 - 172 = -157
-157 ÷ 172 = -0.9127906976744186
-0.9127906976744186 x 100 = -91.28%