5.6% on the actuarial table https://www.ssa.gov/oact/STATS/table4c6.html

@JonathanRay There are also many ailments which could lead to him leaving the presidency without actually dying

I'd probably price this market at 90% on health considerations alone

But also being a rich person with better medical care and no current major morbidities raises his life expectancy above the actuarial table average

@Gen it's possible in principle for a president to have to leave office for medical reasons without dying, but the outside view here is zero out of 46