I don't have access, but I have a couple thoughts on this.
There is revenue, and then there is profit. Profit equals revenue minus expenses.
KYW is a top billing station in the market. It's also probably the most expensive station to run with its staff of anchors, reporters, editors, etc. and the associated equipment costs.
So, while figures are available on which stations bring in the most revenue, I'm not sure we have any reliable figures on which stations are the most profitable.
Radio 104.5 has, what, two full-time jocks? Most of the time it's voice tracked. It shares resources with 5 other (4 fm 1 am) CC stations in the market. If the two jocks voice track other markets, CC is saving money on that, too.
While 18th in revenue might not sound too good, for all we know, CC is pretty happy with its profits from the station. It looks pretty cheap to run.
And the adult-leaning alternative on 104.5 has been the most steady format the station has had in eons. There was the brief attempt at a Spanish music format as WUBA. Then, literally for decades before that, its AC or Hot AC or Adult CHR format was constantly tweaked and was always an also-ran in the philly AC ratings, losing for years first to Magic then to Kiss 100 and finally to B101.
It would seem to me that, in order to get a similar station in NYC, you'd need a group owner with a few FMs in the city, which already has some profitable FMs and would be looking to run the station cheaply with just a couple of jocks.
Or, in other words, as has been written on the NY RadioDiscussions board, you need Pacifica to sell WBAI, an existing NYC group owner to buy it, and for the new owner to identify adult-leaning alternative that targets the suburbs more than the city as a format that it can make a small profit by keeping its operating costs lean.
Could happen. But don't hold your breath.