Which was the best U.S. airline in 2012?

For the past 23 years researchers have been tracking the performance of airlines in the United States and, despite rising prices for airline tickets, last year was one of the best years for the industry.

The Airline Quality Rating, a joint research project by Wichita State University and Purdue University, rates the top 14 carriers in the United States based on on-time performance, baggage handling, involuntary denied boardings, and customer complaints.

While on-time performance and baggage handling improved overall, the industry struggled with involuntary denied boardings and complaints compared to 2011. Still, in 2012, carriers had their second-best year, according to the findings. Only 2011 had better airline performance.

Here's the overall rankings:

1. Virgin America
2. JetBlue
3. AirTran
4. Delta
5. Hawaiian
6. Alaska
7. Frontier
8. Southwest
9. U.S. Airways
10. American
11. American Eagle
12. SkyWest
13. ExpressJet
14. United

For on-time boarding, the group collectively improved from 80 percent in 2011 to 81.8 percent in 2012. Hawaiian lead the way with planes running on time 93.4 percent of the time. The other industry improvement, baggage handling, saw the number of mishandled bags decrease from 3.35 per 1,000 customers in 2011 to 3.07 last year. Virgin America had the lowest rate with 0.87 per 1,000.

But the industry also saw customer complaints rise (mostly for flight problems) from 1.19 per 100,000 to 1.43 last year. Southwest recorded the fewest with 0.25. Involuntary denied boardings also saw a spike: 0.78 per 10,000 passengers to 0.97 in 2012. But JetBlue led this category with only 0.01.

Can we expect this recent trend of record airline performance to continue? Maybe not if air traffic demand grows.

"When you look at the past 13 years, you find that the airline industry performs most efficiently when the system isn't stressed by high passenger volume and high number of airplanes in the air," said Dean Headley, an associate professor a Wichita State University, in a statement. "Every time there are more planes in the sky and more people flying, airline performance suffers."

Read the full report here.