-22.22% is the change from 27 to 21
Calculation steps:
[( 21 - 27 ) ÷ 27] x 100 = -22.22%
Formula
Percentage change = [(21 - 27) / 27] x 100
Subtract the new number by the original number
21 - 27 = -6
-6 ÷ 27 = -0.2222222222222222
-0.2222222222222222 x 100 = -22.22%