-99.52% is the change from 840 to 4
Calculation steps:
[( 4 - 840 ) ÷ 840] x 100 = -99.52%
Formula
Percentage change = [(4 - 840) / 840] x 100
Subtract the new number by the original number
4 - 840 = -836
-836 ÷ 840 = -0.9952380952380953
-0.9952380952380953 x 100 = -99.52%