In this thread started by Magnus I posted this comment:
Just a couple of results:
Over 5,000,000 profiles with size < 498
Over 5,625,000 profiles with size < 566
Over 6,250,000 profiles with size < 631
Over 7,500,000 profiles with size < 817
Over 10,000,000 profiles with size < 1743
Over 11,000,000 profiles with size < 4040
I think it can be concluded that over 50% of the profiles is unsourced, or insufficiently sourced.