Re: "Don't need a link. Its common sense."
Yep. Substitute the word "proof" for the words "a link" in your statement, and that pretty much summarizes my image of you.
I asked for the info because I am genuinely interested, and failed to find any info on the subject. Thanks to Tom for taking me seriously! His link, unless I misunderstood its content, didn't really explain who these people were either. Only that they largely come from the poorer segment of the population.
I'm still not ready to accept your earlier premise that services are available to these folks, they know of its existence, and refuse it; your "common sense" be damned.
Your observation on record-keeping is a good one. I'd really like to see the results of it. Might just explain the whole phenomenon.