258.2% is the change from 256 to 917
Calculation steps:
[( 917 - 256 ) ÷ 256] x 100 = 258.2%
Formula
Percentage change = [(917 - 256) / 256] x 100
Subtract the new number by the original number
917 - 256 = 661
661 ÷ 256 = 2.58203125
2.58203125 x 100 = 258.2%