13.57% is the change from 221 to 251
Calculation steps:
[( 251 - 221 ) ÷ 221] x 100 = 13.57%
Formula
Percentage change = [(251 - 221) / 221] x 100
Subtract the new number by the original number
251 - 221 = 30
30 ÷ 221 = 0.13574660633484162
0.13574660633484162 x 100 = 13.57%