Attorney General Eric Holder's repeated flirtation with leaving his post renewed on Thursday when Holder pledged to stay through the midterm elections, as The Washington Post reports. Curious about how long cabinet members usually stay in their positions — do they usually leave in year six? — I decided to figure it out.

The long story short is that, based on data from the last three presidents, a year-six departure is indeed abnormal. (Many leave at the start of the second term, in year five.) The only other three to do so were under President Bush: Interior Secretary Gale Norton, Transportation Secretary Norm Mineta (who began in the job under Clinton), and, most famously, Defense Secretary Donald Rumsfeld.

What's more, if Holder were to stay through 2017, Obama would trump his two predecessors in the number of original Cabinet members to make it to the end, with five. (Clinton had four. Bush had just one, Labor Secretary and Senate Majority Leader Mitch McConnell spouse Elaine Chao.) Meaning that Holder leaving would threaten Obama's record for Most Full-Term Cabinet Members Among 21st Century Presidents, which is admittedly not much of a record.

Here's the chart, with tenure lengths rounded to the half-year. The most consistent pattern is among secretaries of state, who were all replaced in year five. The most inconsistent? Commerce. And then there's DHS, which didn't exist under Clinton.