-99.53% is the change from 639 to 3
Calculation steps:
[( 3 - 639 ) ÷ 639] x 100 = -99.53%
Formula
Percentage change = [(3 - 639) / 639] x 100
Subtract the new number by the original number
3 - 639 = -636
-636 ÷ 639 = -0.9953051643192489
-0.9953051643192489 x 100 = -99.53%