-35.99% is the change from 639 to 409
Calculation steps:
[( 409 - 639 ) ÷ 639] x 100 = -35.99%
Formula
Percentage change = [(409 - 639) / 639] x 100
Subtract the new number by the original number
409 - 639 = -230
-230 ÷ 639 = -0.3599374021909233
-0.3599374021909233 x 100 = -35.99%