9.24% is the change from 660 to 721
Calculation steps:
[( 721 - 660 ) ÷ 660] x 100 = 9.24%
Formula
Percentage change = [(721 - 660) / 660] x 100
Subtract the new number by the original number
721 - 660 = 61
61 ÷ 660 = 0.09242424242424242
0.09242424242424242 x 100 = 9.24%