55.34% is the change from 309 to 480
Calculation steps:
[( 480 - 309 ) ÷ 309] x 100 = 55.34%
Formula
Percentage change = [(480 - 309) / 309] x 100
Subtract the new number by the original number
480 - 309 = 171
171 ÷ 309 = 0.5533980582524272
0.5533980582524272 x 100 = 55.34%