-74.71% is the change from 340 to 86
Calculation steps:
[( 86 - 340 ) ÷ 340] x 100 = -74.71%
Formula
Percentage change = [(86 - 340) / 340] x 100
Subtract the new number by the original number
86 - 340 = -254
-254 ÷ 340 = -0.7470588235294118
-0.7470588235294118 x 100 = -74.71%