-61.29% is the change from 31 to 12
Calculation steps:
[( 12 - 31 ) ÷ 31] x 100 = -61.29%
Formula
Percentage change = [(12 - 31) / 31] x 100
Subtract the new number by the original number
12 - 31 = -19
-19 ÷ 31 = -0.6129032258064516
-0.6129032258064516 x 100 = -61.29%