-72.22% is the change from 54 to 15
Calculation steps:
[( 15 - 54 ) ÷ 54] x 100 = -72.22%
Formula
Percentage change = [(15 - 54) / 54] x 100
Subtract the new number by the original number
15 - 54 = -39
-39 ÷ 54 = -0.7222222222222222
-0.7222222222222222 x 100 = -72.22%