-91.8% is the change from 512 to 42
Calculation steps:
[( 42 - 512 ) ÷ 512] x 100 = -91.8%
Formula
Percentage change = [(42 - 512) / 512] x 100
Subtract the new number by the original number
42 - 512 = -470
-470 ÷ 512 = -0.91796875
-0.91796875 x 100 = -91.8%