-68.54% is the change from 639 to 201
Calculation steps:
[( 201 - 639 ) ÷ 639] x 100 = -68.54%
Formula
Percentage change = [(201 - 639) / 639] x 100
Subtract the new number by the original number
201 - 639 = -438
-438 ÷ 639 = -0.6854460093896714
-0.6854460093896714 x 100 = -68.54%