Miami International Airport says it had a record-breaking year for cargo volume in 2021.

During the year, cargo volume increased 17 percent to 2.7 million tons in 2021, the most ever handled by the airport.

The growth helped MIA rank as the busiest airport in the U.S. for international freight last year, and the ninth busiest in the world. MIA has regularly been atop the U.S. rankings for international freight for years now.

International freight grew by 17 percent to 2.2 million tons, while domestic freight rose 15 percent to 500,000 tons.

Two major cargo carriers, DHL and Fedex, doubled their operations at the airport last year.

FedEx spent $72.2-million on a 138,000 square-foot expansion of its MIA facility, which doubled in size to more than 282,000 square feet. The expansion was completed in December, adding hundreds of jobs.

DHL spent $78 million on its expansion, nearly doubling its facility size to 206,000 square feet. The work was completed in November. DHL also upped its MIA employee count last year to 731, an increase of 70 percent.