-23.63% is the change from 842 to 643
Calculation steps:
[( 643 - 842 ) ÷ 842] x 100 = -23.63%
Formula
Percentage change = [(643 - 842) / 842] x 100
Subtract the new number by the original number
643 - 842 = -199
-199 ÷ 842 = -0.23634204275534443
-0.23634204275534443 x 100 = -23.63%