-85.54% is the change from 83 to 12
Calculation steps:
[( 12 - 83 ) ÷ 83] x 100 = -85.54%
Formula
Percentage change = [(12 - 83) / 83] x 100
Subtract the new number by the original number
12 - 83 = -71
-71 ÷ 83 = -0.8554216867469879
-0.8554216867469879 x 100 = -85.54%