Des Moines International Airport’s October passenger traffic rose 3.4 percent over the same month last year. Year-to-date, passenger traffic is up 3.7 percent. Frontier Airlines has seen the largest percentage gain this year, up 86.2 percent. Three other airlines are in low single digits for percentage growth in passenger traffic: Allegiant Air, Delta Air Lines and American Airlines. Two airlines’ passenger counts are down slightly for the year: Southwest Airlines and United Airlines. Cargo is down nearly 20 percent for the year.