33.98% is the change from 512 to 686
Calculation steps:
[( 686 - 512 ) ÷ 512] x 100 = 33.98%
Formula
Percentage change = [(686 - 512) / 512] x 100
Subtract the new number by the original number
686 - 512 = 174
174 ÷ 512 = 0.33984375
0.33984375 x 100 = 33.98%