6.45% is the change from 310 to 330
Calculation steps:
[( 330 - 310 ) ÷ 310] x 100 = 6.45%
Formula
Percentage change = [(330 - 310) / 310] x 100
Subtract the new number by the original number
330 - 310 = 20
20 ÷ 310 = 0.06451612903225806
0.06451612903225806 x 100 = 6.45%