-30.83% is the change from 639 to 442
Calculation steps:
[( 442 - 639 ) ÷ 639] x 100 = -30.83%
Formula
Percentage change = [(442 - 639) / 639] x 100
Subtract the new number by the original number
442 - 639 = -197
-197 ÷ 639 = -0.3082942097026604
-0.3082942097026604 x 100 = -30.83%