-90.02% is the change from 511 to 51
Calculation steps:
[( 51 - 511 ) ÷ 511] x 100 = -90.02%
Formula
Percentage change = [(51 - 511) / 511] x 100
Subtract the new number by the original number
51 - 511 = -460
-460 ÷ 511 = -0.9001956947162426
-0.9001956947162426 x 100 = -90.02%