31.19% is the change from 638 to 837
Calculation steps:
[( 837 - 638 ) ÷ 638] x 100 = 31.19%
Formula
Percentage change = [(837 - 638) / 638] x 100
Subtract the new number by the original number
837 - 638 = 199
199 ÷ 638 = 0.31191222570532917
0.31191222570532917 x 100 = 31.19%