-83.56% is the change from 511 to 84
Calculation steps:
[( 84 - 511 ) ÷ 511] x 100 = -83.56%
Formula
Percentage change = [(84 - 511) / 511] x 100
Subtract the new number by the original number
84 - 511 = -427
-427 ÷ 511 = -0.8356164383561644
-0.8356164383561644 x 100 = -83.56%