By Emily Filippi-OwenPublished October 15, 2018 10:30am ESTAir traffic tickets are back to historic highs for the first time since the Great Recession, according to data released Tuesday by the Federal Aviation Administration.

Sales of tickets for flights to and from Chicago soared by almost 6 percent during the first quarter of 2019, according the FAA data.

That was the highest quarterly increase since March 2015.

The agency said the spike was due in part to a surge in the number of passengers flying on U.S.-bound flights to the city.

The FAA said the increase in tickets was mainly due to the surge in U.N. flights, which were up by 9 percent during that time.