55.33% is the change from 638 to 991
Calculation steps:
[( 991 - 638 ) ÷ 638] x 100 = 55.33%
Formula
Percentage change = [(991 - 638) / 638] x 100
Subtract the new number by the original number
991 - 638 = 353
353 ÷ 638 = 0.5532915360501567
0.5532915360501567 x 100 = 55.33%