-0.78% is the change from 512 to 508
Calculation steps:
[( 508 - 512 ) ÷ 512] x 100 = -0.78%
Formula
Percentage change = [(508 - 512) / 512] x 100
Subtract the new number by the original number
508 - 512 = -4
-4 ÷ 512 = -0.0078125
-0.0078125 x 100 = -0.78%