Okay, looks like this was explained back in 2019 by Mother Jones.

Wish they were IT administrators instead of administrative assistants or whatever… but currently, people seem to have three managers (or office administrators) for one person actually doing the job. At my old job there was an IT guy going around threatening people he’ll replace them with a shell script. First they didn’t believe him, then they fired him when he actually did it. He now runs a unicorn startup with twenty employees.

This raises a lot of red flags. Why the monumental rise in the 91-94 period? Why weren’t the various nurse positions included? What is the definition of administrator, and are there differences over the years in how it is counted? Also, the data only extends to 2009, so the entire ACA era is missing.