-91.33% is the change from 173 to 15
Calculation steps:
[( 15 - 173 ) ÷ 173] x 100 = -91.33%
Formula
Percentage change = [(15 - 173) / 173] x 100
Subtract the new number by the original number
15 - 173 = -158
-158 ÷ 173 = -0.9132947976878613
-0.9132947976878613 x 100 = -91.33%