Are apartment-dwellers the new "unsaved"?
The numbers don't seem to add up, but it probably comes down to what you consider a Christian. This 2009 poll came up with the number of Christians in America at 76%, total. If we break out the napkin, the laws of math suggest that it would take 170% of home-dwellers being Christian to balance things out.
Another view would be to assume the 5% "saved" number is correct, assume the best for single-family home dwellers (let's say 80% "saved") and you arrive at an America where a mere 37% of the nation is saved. Clearly, that would indicate a very different world around most of us reading this sentence if that were the case.
It would certainly make sense to me that even accounting for differing definitions of what it means to be "saved" for any given poll, the 5% calculation is wildly off-base. While it would be a secure assumption that younger, less rooted individuals and families might not be as mature, decided, or secure in their faith ... I'm guessing that the expectation of such a bleak scenario might be too much. But then again, I live in a heavily Muslim part of town, so I'm sure I could find bring the average down with any findings I might get in my 'hood.