-87.18% is the change from 312 to 40
Calculation steps:
[( 40 - 312 ) ÷ 312] x 100 = -87.18%
Formula
Percentage change = [(40 - 312) / 312] x 100
Subtract the new number by the original number
40 - 312 = -272
-272 ÷ 312 = -0.8717948717948718
-0.8717948717948718 x 100 = -87.18%