U.S. airlines carried 373.2 million passengers on domestic and international routes in the first six months of 2014, a 2 percent increase over the same period last year, according to data released today by the U.S. Bureau of Transportation Statistics.

Although domestic routes account for the majority of market share, up 1.8 percent to 323.5 million passengers, international routes saw slightly more growth, up 3.7 percent to 49.7 million passengers.

Every month, the Bureau of Transportation Statistics releases data regarding recent travel activity, including details about passenger traffic on U.S. airlines. This is the most recent data available.

Load factor was at an all-time high for the January to June period. Systemwide (83.2 percent) and domestic (84.6 percent) load factors were record highs, surpassing previous highs set in 2013, but international load factor (80.3 percent) was slightly down.

Demand, measured in revenue passenger-miles, reached a new high for the six-month period for systemwide, domestic and international flights.

Delta Air Lines carried the highest volume of systemwide passengers, Southwest carried the most passengers on domestic flights, and United flew the most passengers on international flights.

As expected, Hartsfield-Jackson Atlanta processed the most domestic passengers in the first six months of the year. More international passengers boarded U.S. carriers at Miami International than any other airport — a sign of the destination’s growing popularity among Latin American travelers.

In June, U.S. carriers increased the number of passengers served by 2.2 percent to 68.6 million systemwide compared with a year earlier. This was the second-highest volume of passengers onboard U.S. airlines since June 2007, marking a return to pre-recession level demand.

Photo Credit: The tail sections of an American Airlines and US Airways aircraft are on the ramp at Dallas-Ft Worth International Airport. Mike Stone / Reuters