-37.5% is the change from 512 to 320
Calculation steps:
[( 320 - 512 ) ÷ 512] x 100 = -37.5%
Formula
Percentage change = [(320 - 512) / 512] x 100
Subtract the new number by the original number
320 - 512 = -192
-192 ÷ 512 = -0.375
-0.375 x 100 = -37.5%