-90.04% is the change from 512 to 51
Calculation steps:
[( 51 - 512 ) ÷ 512] x 100 = -90.04%
Formula
Percentage change = [(51 - 512) / 512] x 100
Subtract the new number by the original number
51 - 512 = -461
-461 ÷ 512 = -0.900390625
-0.900390625 x 100 = -90.04%