164.4% is the change from 309 to 817
Calculation steps:
[( 817 - 309 ) ÷ 309] x 100 = 164.4%
Formula
Percentage change = [(817 - 309) / 309] x 100
Subtract the new number by the original number
817 - 309 = 508
508 ÷ 309 = 1.6440129449838188
1.6440129449838188 x 100 = 164.4%