-99.69% is the change from 641 to 2
Calculation steps:
[( 2 - 641 ) ÷ 641] x 100 = -99.69%
Formula
Percentage change = [(2 - 641) / 641] x 100
Subtract the new number by the original number
2 - 641 = -639
-639 ÷ 641 = -0.9968798751950078
-0.9968798751950078 x 100 = -99.69%