-29.58% is the change from 639 to 450
Calculation steps:
[( 450 - 639 ) ÷ 639] x 100 = -29.58%
Formula
Percentage change = [(450 - 639) / 639] x 100
Subtract the new number by the original number
450 - 639 = -189
-189 ÷ 639 = -0.29577464788732394
-0.29577464788732394 x 100 = -29.58%