What is Justice Scalia's life expectancy?

According to the Bureau of Vital Statistics Scalia who is 73 years old, has a life expectancy of 12 years. So, all things being equal he would be expected to live until the Age of 85. If Obama is a two term President, at the end of his tenure Scalia would be 81, so if he were able to stay in office he would be 85 before the end of Obama's successor's term. However the fact that he's fat would count against him, so actuarily Obama would not be in a position to appoint his successor expect if something happened