(CNN) -- It seems the airlines are doing something right. U.S. air carriers posted all-time lows for the number of mishandled bags and bumped passengers in 2011, according to reports released Tuesday.
The 2011 rate of mishandled bags represents the best performance by the airlines in that category since the Department of Transportation started collecting data about luggage in 1988, according to trade group Airlines for America. Last year, there were 3.39 reports of mishandled bags per 1,000 passengers, compared with 3.51 in 2010.
The rate of bumped passengers also reached a record low since the department started collecting data in 1995, A4A says. The rate of bumped passengers dropped to 0.81 per 10,000 passengers in 2011 versus 1.09 in 2010. The airline industry trade group is highlighting numbers released Tuesday in the Department of Transportation's Air Travel Consumer Report.
"Our members are committed to and are delivering levels of safety and customer service that no other industry, given its complexity, matches and the airlines are working to improve on that every day," said Nicholas Calio, A4A president and CEO, in a statement.
The number of consumer complaints against U.S. carriers held steady at 7,465 in 2011, although the rate of complaints per 100,000 passengers dropped slightly from 2010. Southwest Airlines had the lowest rate of complaints among U.S. airlines with just 0.32 complaints per 100,000 passengers. United Airlines had the highest number with 2.21 complaints per 100,000 passengers.
Year-over-year on-time performance was steady, hovering around 80%.
December, however, was a standout month, with the best on-time record (84.4%) and lowest flight cancellation rate (0.8%) for the month of December since the department started collecting comparable data 17 years ago, according to the agency. In December 2010, a month with high passenger volume and frequent bad weather, only 72% of flights arrived on time, and 3.7% of flights were canceled. The fourth quarter of 2011's on-time rate was also the best of any fourth quarter, according to A4A.
The Department of Transportation's new report covers December 2011 as well as the full calendar year.