-96.09% is the change from 511 to 20
Calculation steps:
[( 20 - 511 ) ÷ 511] x 100 = -96.09%
Formula
Percentage change = [(20 - 511) / 511] x 100
Subtract the new number by the original number
20 - 511 = -491
-491 ÷ 511 = -0.9608610567514677
-0.9608610567514677 x 100 = -96.09%