-50.71% is the change from 631 to 311
Calculation steps:
[( 311 - 631 ) ÷ 631] x 100 = -50.71%
Formula
Percentage change = [(311 - 631) / 631] x 100
Subtract the new number by the original number
311 - 631 = -320
-320 ÷ 631 = -0.5071315372424723
-0.5071315372424723 x 100 = -50.71%