18.8% is the change from 686 to 815
Calculation steps:
[( 815 - 686 ) ÷ 686] x 100 = 18.8%
Formula
Percentage change = [(815 - 686) / 686] x 100
Subtract the new number by the original number
815 - 686 = 129
129 ÷ 686 = 0.1880466472303207
0.1880466472303207 x 100 = 18.8%