-62.2% is the change from 82 to 31
Calculation steps:
[( 31 - 82 ) ÷ 82] x 100 = -62.2%
Formula
Percentage change = [(31 - 82) / 82] x 100
Subtract the new number by the original number
31 - 82 = -51
-51 ÷ 82 = -0.6219512195121951
-0.6219512195121951 x 100 = -62.2%