99.6% is the change from 249 to 497
Calculation steps:
[( 497 - 249 ) ÷ 249] x 100 = 99.6%
Formula
Percentage change = [(497 - 249) / 249] x 100
Subtract the new number by the original number
497 - 249 = 248
248 ÷ 249 = 0.9959839357429718
0.9959839357429718 x 100 = 99.6%