-20.12% is the change from 512 to 409
Calculation steps:
[( 409 - 512 ) ÷ 512] x 100 = -20.12%
Formula
Percentage change = [(409 - 512) / 512] x 100
Subtract the new number by the original number
409 - 512 = -103
-103 ÷ 512 = -0.201171875
-0.201171875 x 100 = -20.12%