19.85% is the change from 680 to 815
Calculation steps:
[( 815 - 680 ) ÷ 680] x 100 = 19.85%
Formula
Percentage change = [(815 - 680) / 680] x 100
Subtract the new number by the original number
815 - 680 = 135
135 ÷ 680 = 0.19852941176470587
0.19852941176470587 x 100 = 19.85%