Literally, a "census" of "condition" for a particular VAM would be a full list of all known examples (individual coins) of that variety by condition. However, Condition Census in its everyday usage refers only to the list of the top known examples of the variety by condition.
A Condition Census for a particular VAM might read as follows:
PCGS 66, NGC 65, ANACS 65, raw 64, PCGS 63, raw 63
This means that the highest-grade example of this particular VAM currently known is in MS-66 condition. The actual coin is in a PCGS slab/holder.
In some condition census listings, the grading services may be abbreviated: 63P, 62N, 62A, 61S, 60R with the letters being: P=PCGS, N=NGC, A=ANACS, I=IGC, R=Raw.
Please click this link for the full VAMworld.com definitions page.