51.21% is the change from 660 to 998
Calculation steps:
[( 998 - 660 ) ÷ 660] x 100 = 51.21%
Formula
Percentage change = [(998 - 660) / 660] x 100
Subtract the new number by the original number
998 - 660 = 338
338 ÷ 660 = 0.5121212121212121
0.5121212121212121 x 100 = 51.21%