12.91% is the change from 550 to 621
Calculation steps:
[( 621 - 550 ) ÷ 550] x 100 = 12.91%
Formula
Percentage change = [(621 - 550) / 550] x 100
Subtract the new number by the original number
621 - 550 = 71
71 ÷ 550 = 0.1290909090909091
0.1290909090909091 x 100 = 12.91%