"Between 1800 and 2000 life expectancy at birth rose from about 30 years to a global average of 67 years, and to more than 75 years in favored countries. This dramatic change was called a health transition, characterized by a transition both in how long people expected to live, and how they expected to die. Rising Life Expectancy examines the way humans reduced risks to their survival, both regionally and globally, to promote world population growth and population aging."