297.66% is the change from 128 to 509
Calculation steps:
[( 509 - 128 ) ÷ 128] x 100 = 297.66%
Formula
Percentage change = [(509 - 128) / 128] x 100
Subtract the new number by the original number
509 - 128 = 381
381 ÷ 128 = 2.9765625
2.9765625 x 100 = 297.66%