67.32% is the change from 306 to 512
Calculation steps:
[( 512 - 306 ) ÷ 306] x 100 = 67.32%
Formula
Percentage change = [(512 - 306) / 306] x 100
Subtract the new number by the original number
512 - 306 = 206
206 ÷ 306 = 0.673202614379085
0.673202614379085 x 100 = 67.32%