81.97% is the change from 366 to 666
Calculation steps:
[( 666 - 366 ) ÷ 366] x 100 = 81.97%
Formula
Percentage change = [(666 - 366) / 366] x 100
Subtract the new number by the original number
666 - 366 = 300
300 ÷ 366 = 0.819672131147541
0.819672131147541 x 100 = 81.97%