-31.61% is the change from 639 to 437
Calculation steps:
[( 437 - 639 ) ÷ 639] x 100 = -31.61%
Formula
Percentage change = [(437 - 639) / 639] x 100
Subtract the new number by the original number
437 - 639 = -202
-202 ÷ 639 = -0.3161189358372457
-0.3161189358372457 x 100 = -31.61%