-83.2% is the change from 512 to 86
Calculation steps:
[( 86 - 512 ) ÷ 512] x 100 = -83.2%
Formula
Percentage change = [(86 - 512) / 512] x 100
Subtract the new number by the original number
86 - 512 = -426
-426 ÷ 512 = -0.83203125
-0.83203125 x 100 = -83.2%