Arney... this is just a guess on my part, and don't have any hard data, but like NightHiker commented about specific locations, most of the long time Florida residents that do evacuate don't go very far... Hurricane Andrew in 92, caused most communities to upgrade their building codes, and as evidenced by Charley in 04 that came ashore in Charlotte county as a Cat 4 even "manufactured homes" withstood the 140-150 mph winds with good accounting of themselves.

after each of the storms in 04/05 I did a lessons learned with my students, and those that evacuated typically went to friends or relatives within 15 miles...I live on the central Gulf coast about 35miles north of Tampa, about 3 miles inland at 34' elevation...those living on the barrier islands (especially with access only by a single bridge) and coastal areas threatened by storm surge just move inland

those living in the storm surge areas and locations subject to fresh water flooding are pretty much aware of the problems..we have excellent hurricane wind velocity warnings and most of the spaghetti models of predicted tracks are pretty darn good when they get in the Gulf... 04/05 was unusual in that Polk county which is inland had all 4 cross through

I think that most share my bug out requirement...I plan to stay for a 3 and move to a more hardened structure (relatives place) for a 4 or 5, but not too far...