-7.92% is the change from 240 to 221
Calculation steps:
[( 221 - 240 ) ÷ 240] x 100 = -7.92%
Formula
Percentage change = [(221 - 240) / 240] x 100
Subtract the new number by the original number
221 - 240 = -19
-19 ÷ 240 = -0.07916666666666666
-0.07916666666666666 x 100 = -7.92%