The oil-rich West African nation of Angola has a dubious distinction. Its child mortality rate is the world's worst: 157 kids out of every 1,000 die before their 5th birthday. By comparison the child mortality rate in the U.S. is 7 deaths per 1,000. In Europe it's between 3 and 4.

The numbers are part of a report with a mix of promising and depressing news. Things are far better now than they used to be. Back in 1990, almost 13 million children under age 5 died. Aggressive efforts to improve pediatric health in some of the poorest parts of the world have been partly responsible for bringing that number down to an estimated 6 million this year.

But geography is a killer. "A child born in a low-income country is, on average, 11 times as likely to die before the age of 5 as a child in a high-income country," according to the report.

The most significant progress on child mortality globally over the last 25 years was recorded in Asia and Latin America but some African nations made great strides. Liberia, Malawi and Rwanda all saw their child mortality rates drop by roughly 75 percent over this period. But the top pediatric killers globally remain diseases that disproportionately hit African children — malaria, diarrhea and pneumonia.

The report also notes that most of these kids pass away in their first month of life.

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