-45.19% is the change from 312 to 171
Calculation steps:
[( 171 - 312 ) ÷ 312] x 100 = -45.19%
Formula
Percentage change = [(171 - 312) / 312] x 100
Subtract the new number by the original number
171 - 312 = -141
-141 ÷ 312 = -0.4519230769230769
-0.4519230769230769 x 100 = -45.19%