Life expectancy in the United States increased as of 2012, (the last year for which there is data). Babies born in 2012 have an average life expectancy of 78.8 years, although baby girls can expect to outlive baby boys by almost five years, the same additional span as babies born in 2011, according to the U.S. Centers for Disease Control and Prevention (CDC), which released the new statistics. (Baby girls born in 2012 have a life expectancy of 81.2 years while boys can look forward to an average of 76.4 years). The reason for the uptick: declines in mortality rates for the two leading causes of death - heart disease and cancer. These two diseases now account for 46.5 percent of all deaths. The CDC also determined that a woman who was 65 in 2012 could expect to live 20.5 more years while men who were 65 in 2012 could look forward to 17.9 more years. In other good news, the CDC reported that the infant mortality rate dropped by 1.5 percent in 2012 to a historic low of 597.8 infant deaths per 100,000 live births.