-73.68% is the change from 57 to 15
Calculation steps:
[( 15 - 57 ) ÷ 57] x 100 = -73.68%
Formula
Percentage change = [(15 - 57) / 57] x 100
Subtract the new number by the original number
15 - 57 = -42
-42 ÷ 57 = -0.7368421052631579
-0.7368421052631579 x 100 = -73.68%