Life Expectancy is the sort of statistic that simply cannot rise indefinitely. We are not going to live to be 1000... or even 200. If it doesn't rise, it will inevitably fall sometimes- depending on many circumstances. I assume that IF we had no wars, no murders, no drug abuse.... AND could control pollution, continue to find disease solutions and stabilize population growth... we could raise the Life Expectancy to over 90.
   I also do not see, given human nature, any way that stabilizing population growth can be easily compatible with all of those individually 'good' advances. Personally, I am in my late 70s, with pretty good genetic heritage and *knock wood* no major health problems. I might well make it to 90 or so... but *shrug*...