65.8% is the change from 307 to 509
Calculation steps:
[( 509 - 307 ) ÷ 307] x 100 = 65.8%
Formula
Percentage change = [(509 - 307) / 307] x 100
Subtract the new number by the original number
509 - 307 = 202
202 ÷ 307 = 0.6579804560260586
0.6579804560260586 x 100 = 65.8%