For the first time in almost half a century, homicide has fallen off the list of the nation's top 15 causes of death. The 2010 list, released by the government [on January 11], reflects at least two major trends: Murders are down, and deaths from certain diseases are on the rise as the population ages, health authorities said. This is the first time since 1965 that homicide failed to make the list, according to the Centers for Disease Control and Prevention. The government has been keeping a list of the top causes of death since 1949. Homicide has historically ranked fairly low. It was as high as 10th in 1989 and in 1991 through 1993, when the nation saw a surge in youth homicides related to the crack epidemic. In the past decade, homicide's highest ranking was 13th. That was in 2001 and was due in part to the 9/11 attacks. Murders have been declining nationally since 2006, according to FBI statistics. Criminologists have debated the reasons but believe several factors may be at work. Among them: Abusive relationships don't end in murder as often as they once did, thanks to increased incarcerations and better, earlier support for victims. We've taken the home out of homicide," said James Alan Fox, a Northeastern University criminologist who studies murder data.