Washington Dulles International Airport is still attracting the lion’s share of passengers in the Washington region, but both Reagan National and BWI are catching up.

Ronald Reagan Washington National Airport had 18.8 million passengers fly from its terminals in 2011, a nearly 4 percent increase over 2010, according to the Metropolitan Washington Airports Authority that runs it.

Last week, Maryland officials announced that Baltimore/Washington International Thurgood Marshall Airport had broken its own records, too. The airport had 22.4 million commercial passengers in the calendar year, a 2.1 percent increase over the previous record set in 2010.

Meanwhile, Washington Dulles International Airport served 23.2 million passengers over the course of the year, a 1.6 percent dip from 2010, MWAA said. But the airport did see an 1.6 percent increase in the number of passengers taking international flights.