Passenger traffic at Des Moines International Airport rose 3.6 percent in February and is up 1.7 percent for the year. Part of the reason for the lower-than-usual year-to-date number is that January 2016 was busier than normal, up 9.7 percent from the previous January. So far this year, American Airlines has carried the most passengers at 124,071, but is down 7.3 percent for the year. The biggest percentage gainer was Frontier Airlines, up 175.1 percent. Cargo continued to be soft, dropping 7.1 percent in February and down 9.4 percent for the year.