Passenger traffic last month at Charles M. Schulz–Sonoma County Airport increased 2.2 percent from a year before, though the figures reported Friday show the number of passengers for in the first quarter declined by 2.3 percent from the same pace in 2017.

The county reported 31,484 arriving and departing passengers in March, up from 30,814 the previous March. January through March, passengers totaled 75,602, down from 77,414 last year.

Three airlines currently service the facility, with a fourth, Sun Country, planning to resume its seasonal flights to Minneapolis–St. Paul International Airport in late June.

Of the other carriers, Alaska Airlines was down in passengers counts both in March and the first quarter, county figures show. Last month, the airline carried 24,000 passengers, down 4 percent from 24,995. Through March, Alaska flew 53,136 passengers, down 20.6 percent from 66,903 for that period in 2017.

American Airlines passenger counts rose 3.2 percent last month, while year-to-date counts climbed by 105.5 percent. American Airlines began service between Santa Rosa and Phoenix in February 2017 and added a second flight in July.

United Airlines started Sonoma County flights in June as part of a strategy to draw more North Bay travelers to one of its largest hubs, San Francisco International Airport. The airline carried 3,559 passengers through Santa Rosa in March.

The airport has applied for $650,000 in federal startup funds to partner with United for a nonstop flight to Denver.