30.3% is the change from 66 to 86
Calculation steps:
[( 86 - 66 ) ÷ 66] x 100 = 30.3%
Formula
Percentage change = [(86 - 66) / 66] x 100
Subtract the new number by the original number
86 - 66 = 20
20 ÷ 66 = 0.30303030303030304
0.30303030303030304 x 100 = 30.3%