-39.45% is the change from 512 to 310
Calculation steps:
[( 310 - 512 ) ÷ 512] x 100 = -39.45%
Formula
Percentage change = [(310 - 512) / 512] x 100
Subtract the new number by the original number
310 - 512 = -202
-202 ÷ 512 = -0.39453125
-0.39453125 x 100 = -39.45%