-86.54% is the change from 312 to 42
Calculation steps:
[( 42 - 312 ) ÷ 312] x 100 = -86.54%
Formula
Percentage change = [(42 - 312) / 312] x 100
Subtract the new number by the original number
42 - 312 = -270
-270 ÷ 312 = -0.8653846153846154
-0.8653846153846154 x 100 = -86.54%