99.4% is the change from 500 to 997
Calculation steps:
[( 997 - 500 ) ÷ 500] x 100 = 99.4%
Formula
Percentage change = [(997 - 500) / 500] x 100
Subtract the new number by the original number
997 - 500 = 497
497 ÷ 500 = 0.994
0.994 x 100 = 99.4%
Example