-50% is the change from 216 to 108
Calculation steps:
[( 108 - 216 ) ÷ 216] x 100 = -50%
Formula
Percentage change = [(108 - 216) / 216] x 100
Subtract the new number by the original number
108 - 216 = -108
-108 ÷ 216 = -0.5
-0.5 x 100 = -50%
Example