-50.29% is the change from 173 to 86
Calculation steps:
[( 86 - 173 ) ÷ 173] x 100 = -50.29%
Formula
Percentage change = [(86 - 173) / 173] x 100
Subtract the new number by the original number
86 - 173 = -87
-87 ÷ 173 = -0.5028901734104047
-0.5028901734104047 x 100 = -50.29%