3 ms·

But not humans, regrettably.

• User23 3y ago
  99 year old humans are considerably more likely to live to be 100 than 50 year old humans.
  • Dylan16807 3y ago
    "future longevity" in this case means how many years are left, not how many years total.
• wongarsu 3y ago
  It used to somewhat work for humans, until about the mid-19th century (in Europe, other places vary). A newborn was unlikely to reach an age of 5, a 5 year old had better chances but might still die from illness in childhood, but someone who reached an age of 20 could be expected to reach an age of 40, and if you reached 40 you might well make it to 80.