You know, there is no real way to tell. I've heard of Airstreams out in the AZ desert for darn near a decade in full sun and no issue, while I've heard others have had a type of corrosion issue. FWIW, ours has been indoor except for one winter and the trips we take with it and it may have some clear peeling/corrosion at the cut panel ends in one small spot.
I would keep it clean, keep it Walbernized and keep the tires covered when not in transit, it's the best you can do less putting under something or inside.
Computers manufactured by companies such as IBM, Compaq and millions of others are by far the most popular with about 70 million machines in use worldwide. Macintosh fans note that cockroaches are far more numerous than humans and that numbers alone do not denote a higher life form. -NY Times 11/91