Current processing timeline for I-485 and premium processing

[gr2004]

We have applied for my parents' Green card and their I-130 has been approved with I-485 still pending. My father's case has turned into Interview scheduling but havent received any notice for the interview date and my mother's status still shows "Case was received". They both did the bio-metric finger printing before x-mas. How long is it currently taking? Is there a way to do a premium processing to expedite I-485?

Thanks a lot for all the help.