There are 500 C5 and 140 C6 Wormholes sites. Are all the sleeper sites being fought over?

[Izkinder_Kahn]

I want to get into the business of using Naglfars to clear out c5 and c6 sleeper sites. My question is, since it seems that most of WH space has already been claimed by corps, can I still find plenty of C5 and C6 sites to clear for isk? Or is it packed in WH space and sleeper sites are usually really busy.