21.8% is the change from 665 to 810
Calculation steps:
[( 810 - 665 ) ÷ 665] x 100 = 21.8%
Formula
Percentage change = [(810 - 665) / 665] x 100
Subtract the new number by the original number
810 - 665 = 145
145 ÷ 665 = 0.21804511278195488
0.21804511278195488 x 100 = 21.8%