Passenger traffic at the Colorado Springs Airport took a turn for the worse as declines worsened in May to 13.7 percent from a 10.5 percent drop in April and an 11.9 percent fall in March when compared with a year earlier.

While five airlines reported declining traffic levels from a year ago and two others posted small gains, Denver-based Frontier Airlines boosted its passenger numbers by 20.9 percent from a year earlier to become the airport's third-largest carrier in May.

Traffic for the first five months of the year was down 13.9 percent from a year ago to 348,568 passengers.