-83.59% is the change from 512 to 84
Calculation steps:
[( 84 - 512 ) ÷ 512] x 100 = -83.59%
Formula
Percentage change = [(84 - 512) / 512] x 100
Subtract the new number by the original number
84 - 512 = -428
-428 ÷ 512 = -0.8359375
-0.8359375 x 100 = -83.59%