-90.56% is the change from 646 to 61
Calculation steps:
[( 61 - 646 ) ÷ 646] x 100 = -90.56%
Formula
Percentage change = [(61 - 646) / 646] x 100
Subtract the new number by the original number
61 - 646 = -585
-585 ÷ 646 = -0.9055727554179567
-0.9055727554179567 x 100 = -90.56%