-80.96% is the change from 646 to 123
Calculation steps:
[( 123 - 646 ) ÷ 646] x 100 = -80.96%
Formula
Percentage change = [(123 - 646) / 646] x 100
Subtract the new number by the original number
123 - 646 = -523
-523 ÷ 646 = -0.8095975232198143
-0.8095975232198143 x 100 = -80.96%