-81.09% is the change from 915 to 173
Calculation steps:
[( 173 - 915 ) ÷ 915] x 100 = -81.09%
Formula
Percentage change = [(173 - 915) / 915] x 100
Subtract the new number by the original number
173 - 915 = -742
-742 ÷ 915 = -0.8109289617486338
-0.8109289617486338 x 100 = -81.09%