That's a tough question since most rabbits don't die of old age! If they are well cared for and avoid the primary killer of rabbits are all avoidable circumstances  i.e. predators, heat stroke and hairballs, you can expect a dwarf type to live 4 to 7 years (although I have a friend with a barn full of Dwarfs that are 8 and 9 years old!). The larger breeds typically live 5 to 10 years. Many are reporting teenagers these days.

Rabbits kept indoors are not subject to predators and outside they must be housed in a safe place.

Heat Stroke is not an issue for house rabbits but is a real danger for those kept outdoors.  Frozen water bottles, misters and plenty of shade are very effective ways to keep them safe. 

Hairballs or GI Stasis is probably the single most common cause of death in rabbits.  It is imperative that you measure feed intake daily as it is the best indicator of your rabbits' helath.  He will not eat if he is getting a hairball or if he is not drinking.   Contrary to a lot of advise on line I believe that feeding fresh green vegetables is responsible for many cases of GI Stasis.  The vegetables can cause gas and bloating that shuts down the gut.  In 30 years I have never lost a rabbit to GI Stasis and we never feed greens.  We feed lots of hay and MEASURED pellets only.  Flemish GIants will shut down if not allowed adequate exercise.  Their sedentary nature is the problem.

Old Folks:

The oldest buck I had was a Rex and New Zealand cross who was 12 years old when I sold him to another breeder and was still producing 12 and 14 babies to a litter! He ultimately died of heat stroke 3 years later.

The oldest doe I had was a Satin, in excess of 15 years old when she got her hind leg wrapped in a piece of baling twine and gangrene set in before we found her. She survived the gangrene but died the following summer during a week long heat spell over a 100 degrees. Had she not been stressed by the injury, she would probably have outlived me!