100.97% is the change from 309 to 621
Calculation steps:
[( 621 - 309 ) ÷ 309] x 100 = 100.97%
Formula
Percentage change = [(621 - 309) / 309] x 100
Subtract the new number by the original number
621 - 309 = 312
312 ÷ 309 = 1.0097087378640777
1.0097087378640777 x 100 = 100.97%