-99.07% is the change from 646 to 6
Calculation steps:
[( 6 - 646 ) ÷ 646] x 100 = -99.07%
Formula
Percentage change = [(6 - 646) / 646] x 100
Subtract the new number by the original number
6 - 646 = -640
-640 ÷ 646 = -0.9907120743034056
-0.9907120743034056 x 100 = -99.07%