-24.38% is the change from 845 to 639
Calculation steps:
[( 639 - 845 ) ÷ 845] x 100 = -24.38%
Formula
Percentage change = [(639 - 845) / 845] x 100
Subtract the new number by the original number
639 - 845 = -206
-206 ÷ 845 = -0.24378698224852072
-0.24378698224852072 x 100 = -24.38%