-31.14% is the change from 639 to 440
Calculation steps:
[( 440 - 639 ) ÷ 639] x 100 = -31.14%
Formula
Percentage change = [(440 - 639) / 639] x 100
Subtract the new number by the original number
440 - 639 = -199
-199 ÷ 639 = -0.3114241001564945
-0.3114241001564945 x 100 = -31.14%