-5.56% is the change from 18 to 17
Calculation steps:
[( 17 - 18 ) ÷ 18] x 100 = -5.56%
Formula
Percentage change = [(17 - 18) / 18] x 100
Subtract the new number by the original number
17 - 18 = -1
-1 ÷ 18 = -0.05555555555555555
-0.05555555555555555 x 100 = -5.56%