Wikipedia is, in general, a very accurate source. It is essentially the collection of current human knowledge and is as credible as you can get when it comes to information. Of course it has its outliers with certain topics, but the site is far from conjecture.
Just so it's clear about this specific thread. This is an article, not a study.
I don't doubt there is validity in those numbers but it's common scientific practice to disclose methods for acquiring the data as well as giving, at minimum, error bars.
I am definitely believing in what robby has said about hunting the same average unit every year is the ticket, especially now days when specific units and states are pretty much advertised. It seems like the mass urban development and boom of social media into the hunting world has localized...