-81.4% is the change from 215 to 40
Calculation steps:
[( 40 - 215 ) ÷ 215] x 100 = -81.4%
Formula
Percentage change = [(40 - 215) / 215] x 100
Subtract the new number by the original number
40 - 215 = -175
-175 ÷ 215 = -0.813953488372093
-0.813953488372093 x 100 = -81.4%