-15.23% is the change from 512 to 434
Calculation steps:
[( 434 - 512 ) ÷ 512] x 100 = -15.23%
Formula
Percentage change = [(434 - 512) / 512] x 100
Subtract the new number by the original number
434 - 512 = -78
-78 ÷ 512 = -0.15234375
-0.15234375 x 100 = -15.23%