United Airlines is once again the second largest airline in the world thanks to some aggressive growth, Bloomberg reports

Ranked by air miles flown, American Airlines is the largest airline in the world. Delta had assumed second place on the list — long held by United — in 2015. But United has recently embarked on a plan to increase capacity at its Chicago, Houston and Denver hubs, allowing the airline to move ahead of Delta again.

In 2018, United flew 230.2 billion revenue passenger miles, slightly ahead of Delta’s 225.2 billion miles.

“Our goal is not to be the biggest. We want to be the best and as we implement our strategy, we are looking to build on this momentum in 2019,” said a United spokesperson.

In December, United announced the addition of new and expanded service on 11 routes, including beginning flights to Stockton, California, for the first time. Most of the new flights originate in the airline’s Chicago (O’Hare) and Houston hubs.