I want to know the answer to the following question:
How many travelers visited JFK, LaGuardia and Newark Liberty in 2012?
All the background I'm provided with is that "JFK and Newark Liberty were the busiest and fourth busiest U.S. gateways for international air passengers, respectively, in 2012; as of 2011, JFK was the busiest airport for international passengers in North America.". Is that enough to answer the question?