-93.93% is the change from 511 to 31
Calculation steps:
[( 31 - 511 ) ÷ 511] x 100 = -93.93%
Formula
Percentage change = [(31 - 511) / 511] x 100
Subtract the new number by the original number
31 - 511 = -480
-480 ÷ 511 = -0.9393346379647749
-0.9393346379647749 x 100 = -93.93%