It was followed by Japan, Macau, San Marino and Singapore.
The shortest life expectancies were clustered in Sub
, a region that has been hit hard by an epidemic of HIV and AIDS, as well as famine and civil strife. Swaziland has the shortest, at 34.1 years, followed by Zambia, Angola, Liberia and Zimbabwe.
Researchers said several factors have contributed to the United States falling behind other industrialized nations.