Nate Silver ran the numbers on airline terror attempts. This decade, there have been six, including the four 9/11 hijackers, the shoe bomber and the Nigerian guy on Christmas day.
Over the past decade, according to BTS, there have been 99,320,309 commercial airline departures that either originated or landed within the United States. Dividing by six, we get one terrorist incident per 16,553,385 departures.
These departures flew a collective 69,415,786,000 miles. That means there has been one terrorist incident per 11,569,297,667 mles flown. This distance is equivalent to 1,459,664 trips around the diameter of the Earth, 24,218 round trips to the Moon, or two round trips to Neptune.
Remember this the next time you're standing there at the airport with half of your clothing and your dignity wadded up in a gray plastic bin.