-70.09% is the change from 331 to 99
Calculation steps:
[( 99 - 331 ) ÷ 331] x 100 = -70.09%
Formula
Percentage change = [(99 - 331) / 331] x 100
Subtract the new number by the original number
99 - 331 = -232
-232 ÷ 331 = -0.7009063444108762
-0.7009063444108762 x 100 = -70.09%