The VOIDRUNNER'S CODEX is LIVE! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
Look at the title page. You'll see a string of numbers, like 9 8 7 6 5 4 3 2 1. For every printing, they delete one number, so a 3rd printing would be 9 8 7 6 5 4 3. Basically, the lowest number in the sequence is the print run for that particular book.
I am pretty sure only the PHB is into a 6th printing. At least that is the only one they officially announced. I think the other two are still around the 3rd or 4th print range.