99.7% is the change from 331 to 661
Calculation steps:
[( 661 - 331 ) ÷ 331] x 100 = 99.7%
Formula
Percentage change = [(661 - 331) / 331] x 100
Subtract the new number by the original number
661 - 331 = 330
330 ÷ 331 = 0.9969788519637462
0.9969788519637462 x 100 = 99.7%