Current wait times for employment-based I-485's?

I'm currently waiting for the acknowledgement of receipt of my I-485 that was delivered to USCIS in mid-December, and I was wondering what sort of timeframes people are currently seeing for the processing of AOS paperwork on employment-based green card applications?

Mine is an EB1A, but interested to hear from anyone who's gone down the employment-based route recently — this subreddit tends to have more discussion of family-based green card applications.