313.49% is the change from 126 to 521
Calculation steps:
[( 521 - 126 ) ÷ 126] x 100 = 313.49%
Formula
Percentage change = [(521 - 126) / 126] x 100
Subtract the new number by the original number
521 - 126 = 395
395 ÷ 126 = 3.134920634920635
3.134920634920635 x 100 = 313.49%