122.3% is the change from 139 to 309
Calculation steps:
[( 309 - 139 ) ÷ 139] x 100 = 122.3%
Formula
Percentage change = [(309 - 139) / 139] x 100
Subtract the new number by the original number
309 - 139 = 170
170 ÷ 139 = 1.223021582733813
1.223021582733813 x 100 = 122.3%