I can't remember exactly where it was, but I seem to remember it in the high 3-share range.
I understand its last year as 104.3 K-Hits billed just over $6 million. I don't know how well it has done since, but David says it's billing more today. As he has access to that and I haven't had access to Miller-Kaplan in over a decade, he's most likely right.
Granted, The Block is probably doing around $0 right now since it's commercial-free, but I can't imagine it will get anywhere near 104.3 K-Hits or 104-3 Jamz billing unless it really improves!