65.7% is the change from 309 to 512
Calculation steps:
[( 512 - 309 ) ÷ 309] x 100 = 65.7%
Formula
Percentage change = [(512 - 309) / 309] x 100
Subtract the new number by the original number
512 - 309 = 203
203 ÷ 309 = 0.656957928802589
0.656957928802589 x 100 = 65.7%