It seems to me.. (Score 1)

"The overall goal of the parasite is to end up in a feline stomach," If that's the case then you'd expect populations which tend to own more cats (or more Ferrel cats) would have a higher percent. It also goes to reason that if you have more money you are more likely to have a pet (at least within the US) so we have more then just this isolated percent, we have money, percent of population owning cats, and raito of wild cats to people.