-32.08% is the change from 639 to 434
Calculation steps:
[( 434 - 639 ) ÷ 639] x 100 = -32.08%
Formula
Percentage change = [(434 - 639) / 639] x 100
Subtract the new number by the original number
434 - 639 = -205
-205 ÷ 639 = -0.3208137715179969
-0.3208137715179969 x 100 = -32.08%