-62.5% is the change from 24 to 9
Calculation steps:
[( 9 - 24 ) ÷ 24] x 100 = -62.5%
Formula
Percentage change = [(9 - 24) / 24] x 100
Subtract the new number by the original number
9 - 24 = -15
-15 ÷ 24 = -0.625
-0.625 x 100 = -62.5%
Example