Are global forum statistics available for Bitcointalk.org?
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Not too many ofiicial stats are around. The only official global stats are these: https://bitcointalk.org/index.php?action=stats

Specifically, on the topic of merits there are these:
https://bitcointalk.org/index.php?action=merit;stats -> Official
Bitcointalk Merit Dashboard -> Unofficial

There are also plenty of other threads with Merit Stats over the past on Meta by Zentdex, Piggy, LoyceV, sncc, coinlocket$ and myself DdmrDdmr. Check their OPs and they should be visible soon enough.

On forum profiles there is a recent one published this week by mazdafunsun: Truth about bitcointalk users 2.0