-79.31% is the change from 87 to 18
Calculation steps:
[( 18 - 87 ) ÷ 87] x 100 = -79.31%
Formula
Percentage change = [(18 - 87) / 87] x 100
Subtract the new number by the original number
18 - 87 = -69
-69 ÷ 87 = -0.7931034482758621
-0.7931034482758621 x 100 = -79.31%