The Hauntworld numbers are your best bet. There have never been any detailed surveys that were accurate.
Most Haunters do not want to reveil any details because in the past it has come back to bite them in the tail! One survey wanted details, then it was found out the info was being used to determine where someone wanted to put haunts in several states.
On a local level, haunters do not want to release info that can used against them by their competitors.
Unfortunate it's the nature of the business.