Wikipedia in their info on elephants states "About 1200 elephants are kept in western zoos. A study shows that the lifespan of elephants in European zoos is about half as long as those living in protected areas in Africa and Asia.[65]". Members from Europe do you agree?
In any case, in the past very few years there has been such a change in elephant exhibit design and elephant husbandry in North America, that it will be 40 years yet before the current situation can be evaluated!
In my experience, Wikipedia is full of sh*t. In particular, emotive topics, like anything related to animal rights, are a sort of an endless battle. You go morning - a peta filled the page with nonsense. Next morning - opposite views. etc etc.
If somebody has time, he/she can correct some info. Be aware however, that it is constant task - these articles keep changing forever.
(Hmm, I can understand that political topics can change daily. But is it a sign of reliability, that Wikipedia info on elephants and lions changes daily? )