-53.03% is the change from 66 to 31
Calculation steps:
[( 31 - 66 ) ÷ 66] x 100 = -53.03%
Formula
Percentage change = [(31 - 66) / 66] x 100
Subtract the new number by the original number
31 - 66 = -35
-35 ÷ 66 = -0.5303030303030303
-0.5303030303030303 x 100 = -53.03%