-50.32% is the change from 312 to 155
Calculation steps:
[( 155 - 312 ) ÷ 312] x 100 = -50.32%
Formula
Percentage change = [(155 - 312) / 312] x 100
Subtract the new number by the original number
155 - 312 = -157
-157 ÷ 312 = -0.5032051282051282
-0.5032051282051282 x 100 = -50.32%