When Pope Benedict XVI was elected in 2005 at the age of 78 (and 3 days), he was the 7th oldest person elected to the papacy since 1277.*
Since then, he has lived longer than 3 of those 6. Pope Benedict XVI will turn 85 in early April.
The 3 remaining older Popes are: Popes Clement X (86.0), Clement XII (died at 87.8), and Gregory XII (90).
In addition, there are 4 more that were elected Pope at a younger age, but lived longer. These are: Popes Innocent XII (elected at 76.3; died at 85.5), Pius IX (54.1; 85.7), John XXII (72; 90), and Leo XIII (68.0; 93.4).
Pope John Paul II was elected at a younger age (58.4) and died at age 84.9 - slightly younger than Pope Benedict XVI is now.
* 1277 has no special significance except that is where my historical data currently cuts off for Popes.