-60% is the change from 85 to 34
Calculation steps:
[( 34 - 85 ) ÷ 85] x 100 = -60%
Formula
Percentage change = [(34 - 85) / 85] x 100
Subtract the new number by the original number
34 - 85 = -51
-51 ÷ 85 = -0.6
-0.6 x 100 = -60%
Example