63.43% is the change from 309 to 505
Calculation steps:
[( 505 - 309 ) ÷ 309] x 100 = 63.43%
Formula
Percentage change = [(505 - 309) / 309] x 100
Subtract the new number by the original number
505 - 309 = 196
196 ÷ 309 = 0.6343042071197411
0.6343042071197411 x 100 = 63.43%