-86.63% is the change from 621 to 83
Calculation steps:
[( 83 - 621 ) ÷ 621] x 100 = -86.63%
Formula
Percentage change = [(83 - 621) / 621] x 100
Subtract the new number by the original number
83 - 621 = -538
-538 ÷ 621 = -0.8663446054750402
-0.8663446054750402 x 100 = -86.63%