As pointed out in 3.) the mortality hazard h(x) does not increase exponentially at very high ages as it does for ages 30 up to let's 80 or 90. Until then the Gompertz-Makeham hazard h(x)= alpha * exp(betax) + gamma approximates adult mortality very well. At higher ages mortality begins to decelerate and, most likely, reaches a plateau at about age 110.
References:
1) Parametric models for late life mortality:
A useful mortality model, which has a logistic form, is: h(x) = (alpha exp(betax))(1+alpha exp(beta*x)). One can also add an additive term, often denoted as gamma or c. Please see for a comparison for late life models:
http://www.demogr.mpg.de/Papers/Books/Monograph5/start.htm
1) Parametric models for late life mortality:
A useful mortality model, which has a logistic form, is: h(x) = (alpha exp(betax))(1+alpha exp(beta*x)). One can also add an additive term, often denoted as gamma or c. Please see for a comparison for late life models: http://www.demogr.mpg.de/Papers/Books/Monograph5/start.htm
In case you speak German, the German Society of Actuaries has an interesting comparison of models: https://aktuar.de/custom/download/dav/veroeffentlichungen/20...
2) An article which estimates the constant hazard at advanced ages: www.demogr.mpg.de/books/drm/007/3-1.pdf
I hope this helps a bit!