How turnover in the White House is measured varies. Brookings tracks 65 critical positions within the administration, though that misses some important ancillary staffers. (Per Brookings, about half of President Trump’s core staff has left since he was inaugurated.)

Trump critics, like MSNBC’s Rachel Maddow, cram in as many positions as possible. On Thursday night, after the announcement that Trump’s second national security adviser H.R. McMaster was leaving, this is the graphic that Maddow displayed:

Our informal tally falls somewhere in the middle. We’ve tracked a number of key firings and resignations since Trump was inaugurated focused on the political importance of the departures. It includes not only Trump’s team — but also firings like that of Sally Yates, the acting attorney general at the outset of Trump’s presidency. Not on Trump’s team — but important to consider.

What sets McMaster’s departure apart is not only the rhetoric of his replacement John Bolton — though that is certainly significant. What further sets this departure apart is that Trump is queuing up his third national security adviser in 14 months. He’s also had three communications directors (and is looking for his fourth), two chiefs of staff (with the current one apparently out of favor with the president), two press secretaries and two FBI directors.

In other words, by early April there will have been 12 different people who’ve served in those five positions alone.

When we talk about a president’s “team,” we generally think of it as one group of people that works together. But all of this turnover in Trump’s White House means that key staff have spent very little time working with one another. Between his national security adviser, chief of staff, communications directors and press secretary, the longest period of overlap has been less than nine months — McMaster’s overlap with press secretary Sarah Sanders.

(McMaster’s overlap with himself — that is, the extent of his tenure — is 414 days. The other circles are scaled to that figure. Note, too, that the overlap above is only with those individuals serving in the listed capacity.)

McMaster is actually one of the longest-serving members of Trump’s team, having started shortly after the firing of his predecessor Michael Flynn (whose tenure was one of the shortest). He’s worked with two chiefs of staff, all three communications directors and both press secretaries.

Now Bolton moves in. How long he’ll overlap with, say, Chief of Staff John F. Kelly is anyone’s guess. Maybe this is one of the changes that finally brings the tumult in the White House to a rest.

Under no method of tracking that turnover, though, is there any suggestion that it’s about to come to an end.