-84.36% is the change from 991 to 155
Calculation steps:
[( 155 - 991 ) ÷ 991] x 100 = -84.36%
Formula
Percentage change = [(155 - 991) / 991] x 100
Subtract the new number by the original number
155 - 991 = -836
-836 ÷ 991 = -0.8435923309788093
-0.8435923309788093 x 100 = -84.36%