3.24% is the change from 309 to 319
Calculation steps:
[( 319 - 309 ) ÷ 309] x 100 = 3.24%
Formula
Percentage change = [(319 - 309) / 309] x 100
Subtract the new number by the original number
319 - 309 = 10
10 ÷ 309 = 0.032362459546925564
0.032362459546925564 x 100 = 3.24%