Yep, all of the above, and hence every 5 years for me. Also will be 5 years for my sons, and Doc told me to tell them to get it at 40 years old to boot. I actually had the most vivid dream I have ever had while under. I was strolling along the beach at Pedregal in Cabo San Lucas. I could feel the sand on my feet, the breeze blowing by, and hear the waves crashing. It was AWESOME!