The first year of the Trump administration experienced a great deal of staff turnover, with many departures and replacements involving high-profile positions and individuals. According to the Wall Street Journal, those changes amounted to a record-setting year.

The first year of the Trump administration experienced a great deal of staff turnover, with many departures and replacements involving high-profile positions and individuals.
According to the Wall Street Journal, those changes amounted to a record-setting year. 
Kathryn Dunn-Tenpas, a senior fellow at the Brookings Institution, calculated the rate of change among senior officials at 34%.
That's double Ronald Regan's first year, which claims 2nd place. 
Those who left on their own accord—or not—include Michael Flynn, Reince Priebus, Sean Spicer, and Steve Bannon. 
The position of communications director proved to be a particularly challenging one to keep filled. 
Current department head Hope Hicks is the 4th person to serve in the position and was preceded by Anthony Scaramucci, notes the BBC.
Politico reports that according to inside sources, more changes in the White House lineup may very well be coming, and possibly soon. 
What it calls "Season 2 of Trump's West Wing" could see the additions of campaign staffers Corey Lewandowski and David Urban, and the promotion of Kellyanne Conway to chief of staff.