-99.69% is the change from 646 to 2
Calculation steps:
[( 2 - 646 ) ÷ 646] x 100 = -99.69%
Formula
Percentage change = [(2 - 646) / 646] x 100
Subtract the new number by the original number
2 - 646 = -644
-644 ÷ 646 = -0.9969040247678018
-0.9969040247678018 x 100 = -99.69%