288.24% is the change from 255 to 990
Calculation steps:
[( 990 - 255 ) ÷ 255] x 100 = 288.24%
Formula
Percentage change = [(990 - 255) / 255] x 100
Subtract the new number by the original number
990 - 255 = 735
735 ÷ 255 = 2.8823529411764706
2.8823529411764706 x 100 = 288.24%