-71.9% is the change from 306 to 86
Calculation steps:
[( 86 - 306 ) ÷ 306] x 100 = -71.9%
Formula
Percentage change = [(86 - 306) / 306] x 100
Subtract the new number by the original number
86 - 306 = -220
-220 ÷ 306 = -0.7189542483660131
-0.7189542483660131 x 100 = -71.9%