There is a tremendous amount of drama in House Speaker John Boehner's (R-Ohio) sudden announcement that he plans to resign his position. It comes at a busy time in Washington, shortly after the departure of Pope Francis, at the same time as the arrival of the Chinese president and while Boehner's House is battling to figure how and whether to keep the government running.

In the grand sweep of time, however, Boehner's tenure is less remarkable — at least in duration.

Changes in leadership are not common mid-session, often only occurring after a death, but they have happened before. (We looked at this earlier this month when considering the likelihood that Boehner would be ousted.) As a result, on average, speaker tenures usually last some multiple of 365 days. The median number of days of service as speaker is 1,462 — 365 times four (two congressional terms) plus two days. The average number of days of service is 1,554, thanks to Sam Rayburn's very long tenure.

Here's every speaker, ordered by length of tenure. (This is combined, so speakers who lost and then regained power have one big total.)

Rayburn's 6,207 days is longer than the 12 shortest speaker tenures combined.

Not adding much to that total is the guy at the bottom, Theodore Medad Pomeroy, who was speaker of the House from 11 a.m. on March 3, 1869, to noon on March 4 — and that was it. (We talked about that previously; long story short was that the sitting speaker had to go be vice president.)

As a constitutionally designated position, there's always been a speaker. The first was the grandly named Frederick Augustus Conrad Muhlenberg. For a long time, speakers served only for one Congress. The last to do that was John Nance Garner, excluding his two successors who both died in office.

There at the end was John Andrew Boehner, a speaker during a remarkable moment but of unremarkable longevity.