The firing of Secretary of State Rex Tillerson is the latest in a long line of changes in the Trump White House.

The Trump White House has experienced a lot of turnover, though not all of it has been unprecentented, according to PolitiFact.

But Northwestern University political science professor Alvin Tillery said no other presidential administration in the modern era has seen turnover comparable to the first year of Trump’s White House.

“The Trump administration is an extreme outlier, both in their inability to staff positions with people of quality, but also with the series of resignations from the inner circle of the White House,” said Tillery, who specializes in American politics, presidential leadership and diversity issues.

“This is an unprecedented moment in the modern era, where the president can’t find top-quality candidates. . . . This president seems to have the reverse Midas touch.”

Here’s a timeline of some of the most high-profile changes in the White House.