-91.78% is the change from 511 to 42
Calculation steps:
[( 42 - 511 ) ÷ 511] x 100 = -91.78%
Formula
Percentage change = [(42 - 511) / 511] x 100
Subtract the new number by the original number
42 - 511 = -469
-469 ÷ 511 = -0.9178082191780822
-0.9178082191780822 x 100 = -91.78%