-3.07% is the change from 228 to 221
Calculation steps:
[( 221 - 228 ) ÷ 228] x 100 = -3.07%
Formula
Percentage change = [(221 - 228) / 228] x 100
Subtract the new number by the original number
221 - 228 = -7
-7 ÷ 228 = -0.03070175438596491
-0.03070175438596491 x 100 = -3.07%