3.17% is the change from 221 to 228
Calculation steps:
[( 228 - 221 ) ÷ 221] x 100 = 3.17%
Formula
Percentage change = [(228 - 221) / 221] x 100
Subtract the new number by the original number
228 - 221 = 7
7 ÷ 221 = 0.03167420814479638
0.03167420814479638 x 100 = 3.17%