>Your source is for full-time employment.

Number of people employed part-time, not by choice...falling:

https://research.stlouisfed.org/fred2/series/LNS12032196

U6 Unemployment rate...falling:

https://research.stlouisfed.org/fred2/series/U6RATE

From those same charts, unemployed part-time not by choice is rising since Oct '15. U6 is constant in that period as well.

Here's a more up-to-date graph of "part-time for economic reaons": https://research.stlouisfed.org/fred2/series/LNS12032194

We're down to June 2008 levels, but have a ways to go before we hit December 2007 levels.