Source: PRB 2014 and 2015 World Population Data Sheets.
As can be seen by the chart there is still a large difference in statistics between average length of life in third world countries than in many Western countries today.
World life expectancy map shaded by ages
Various factors contribute to an individual's longevity. Significant factors in life expectancy include gender, genetics, access to health care, hygiene, diet and nutrition, exercise, lifestyle, and crime rates.
In preindustrial times, deaths at young and middle age were more common than they are today, and lifespans past 70 years were comparatively rare.
Studies have estimated that approximately 20 to 30% of an individual's lifespan is related to genetics, the rest is due to individual behaviors and environmental factors which can be modified.
Women normally outlive men, and this was as true in pre-industrial times as today. Theories for this include smaller bodies (and thus less stress on the heart), a stronger immune system (since testosterone acts as an immuno-suppressant), and less tendency to engage in physically dangerous activities.
The U.S. Census Bureau view on the future of longevity is that life expectancy in the United States will be in the mid-80s by 2050 (up from 77.85 in 2006) and will top out eventually in the low 90s, barring major scientific advances that can change the rate of human aging itself, as opposed to merely treating the effects of aging as is done today.
According to U.S. Census Bureau statistics, Andorra currently has the world's longest life expectancy of 83.5 years.
Statistically the average life expectancy of all people in the world is currently 66.26 years (64.3 years for males and 68.35 years for females).
Longest Living Persons Include:
Jeralean Talley (born 1899): the oldest living person in the world.
Sarah Knauss (1880 - 1999, 119 years, 97 days): the second oldest documented person in modern times and the oldest American.
Geert Adriaans Boomgaard (1788 - 1899, 110 years, 135 days): first person to reach the age of 110 (on September 21, 1898) and whose age could be validated.
Jiroemon Kimura (1897-2013): celebrated his 116th birthday in April 2013, was the oldest man in history whose age has been verified by modern documentation, and died on 12 June 2013.
Jeanne Calment (1875 - 1997, 122 years, 164 days): the oldest person in history whose age has been verified by modern documentation. This defines the modern human life span, which is set by the oldest documented individual who ever lived.