-30.13% is the change from 312 to 218
Calculation steps:
[( 218 - 312 ) ÷ 312] x 100 = -30.13%
Formula
Percentage change = [(218 - 312) / 312] x 100
Subtract the new number by the original number
218 - 312 = -94
-94 ÷ 312 = -0.30128205128205127
-0.30128205128205127 x 100 = -30.13%