288.63% is the change from 255 to 991
Calculation steps:
[( 991 - 255 ) ÷ 255] x 100 = 288.63%
Formula
Percentage change = [(991 - 255) / 255] x 100
Subtract the new number by the original number
991 - 255 = 736
736 ÷ 255 = 2.8862745098039215
2.8862745098039215 x 100 = 288.63%