-24.73% is the change from 849 to 639
Calculation steps:
[( 639 - 849 ) ÷ 849] x 100 = -24.73%
Formula
Percentage change = [(639 - 849) / 849] x 100
Subtract the new number by the original number
639 - 849 = -210
-210 ÷ 849 = -0.24734982332155478
-0.24734982332155478 x 100 = -24.73%