87.21% is the change from 344 to 644
Calculation steps:
[( 644 - 344 ) ÷ 344] x 100 = 87.21%
Formula
Percentage change = [(644 - 344) / 344] x 100
Subtract the new number by the original number
644 - 344 = 300
300 ÷ 344 = 0.872093023255814
0.872093023255814 x 100 = 87.21%