Roughly 37.5 million passengers passed through the Minneapolis-St. Paul International Airport in 2016, falling just short of the record set 11 years earlier, airport officials announced Wednesday.

Last year's total was up 2.6 percent from '15. The busiest year for the airport was 2005, with 37.6 million passengers.

"The airport's performance mirrors the Upper Midwest's strong economy and continues the trend of rising passenger numbers," said Brian Ryks, executive director and CEO of the Metropolitan Airports Commission, which owns and operates the airport. "New routes offered at MSP also contributed to 2016's uptick. Provided the economy remains strong, we expect that growth to continue in 2017 and beyond."

The rise in traffic is being attributed in part to 20 routes being added by nine airlines. Delta, which operates a hub at MSP, added five routes. American, Sun Country and Spirit Airlines added three each.

Two carriers also started offering service in 2016 from MSP to cities in the Midwest. Air Choice One began service to Ironwood, Mich., Mason City, Iowa, and Fort Dodge, Iowa. Boutique Air launched service to Thief River Falls, Minn.

In 2017, new routes out of MSP already are lined up, including: Southwest's nonstop service to Nashville starting in June; KLM flights to Amsterdam in March; Alaska Airlines service for San Francisco, beginning in July; and Delta flights to Marquette, Mich., starting in March.

About 58 percent of MSP's passengers were on flights that originated at the airport, with the remainder making connections.

Delta (25.8 million passengers) was responsible for more than two-thirds of the passenger traffic at MSP. Next were American (2.4 million), Sun Country (2.2 million), Southwest (2.1 million), United (1.7 million), Spirit (1.2 million), Frontier (328,000) and Alaska (276,000).

Paul Walsh • 612-673-4482