Couch surfing: what do U.S. BLS surveys have to say about it?

According to dictionary.com:

[kouch-surf] couch surfing: sleeping on the couch or extra bed of an acquaintance when traveling or between permanent lodging places, esp. to save money.

Couch surfing, is an alternative way of living and traveling, especially among the young,  There are even websites, like https://www.couchsurfing.org/, dedicated to making couch surfing matches.

The prevalence of couch surfing can be measured to a good degree by U.S BLS Consumer Expenditure Survey data.  The table below shows the break down of who owns outright (1), owns with a mortgage (2), rents (3), stays without rent  (4), and who stays in a dorm (5).