The Wall Street Journal’s annual Middle Seat scorecard ranks U.S. airline performance on seven measures. The results for 2016 show 7 percent fewer flights arrived late in 2016, fewer bags were lost and fewer complaints were filed with the Transportation Department.

The tardiest airline was Spirit at 74 percent, while Alaska was the most punctual with 86 percent of flights on time.

Alaska won overall for best performer for the fourth straight year, slightly beating out Delta Air Lines, which has been positioning itself as a major competitor for Alaska. American, the world’s biggest airline, improved its numbers, but still remains the worst on the scorecard for the second year in a row due to high rates of canceled flights and lost luggage. It has ranked last or next-to-last for all nine years of the scorecard.

Alaska’s poor showing in 2015 for baggage prompted a major overhaul of luggage handling, leading to its scorecard improvement in that area.

Spirit Airlines was the worst in on-time performance and customer complaints, though it’s trying to improve, says Robert Fornaro, chief executive, Spirit Airlines. WSJ says Spirit will likely always rank near the bottom of the DOT complaint list because of its fee structure, which allows customers to add on a slew of items like early boarding and checked baggage. These fees surprise many customers.

For the complete report, visit the Wall Street Journal.