started to drop in 1991 under previous mayor David Dinkins, three years before Giuliani took office. A small but significant nationwide drop in crime also preceded Giuliani's election, and continued throughout the 1990s. Two likely contributing factors to this overall decline in crime were federal funding of an additional 7,000 police officers and an improvement in the national economy. Many experts believe changing demographics were the most significant cause. Some have pointed out that during this time, murders inside the home, which could not be prevented by more police officers, decreased at the same rate as murders outside the home. Also, since the crime index is based on the FBI crime index, which is self-reported by police departments, some have alleged that crimes were shifted into categories that the FBI does not quantify. According to some analyses, the crime rate in New York City fell even more in the 1990s and 2000s than nationwide and therefore credit should be given to a local dynamic: highly focused policing. In this view, as much as half of the reduction in crime in New York in the 1990s, and almost all in the 2000s, is due to policing. Opinions differ on how much of the credit should be given to Giuliani; to Bratton; and to the current Police Commissioner, Ray Kelly, who had previously served under Dinkins and criticized aggressive policing under Giuliani. Among those crediting Giuliani for making New York safer were several other cities nationwide whose police departments subsequently instituted programs similar to Bratton's CompStat. In 2005, Giuliani was reportedly nominated for a Nobel Peace Prize for his efforts to reduce crime rates in the city. The prize went instead to Mohamed ElBaradei and the International Atomic Energy Agency for their efforts to reduce nuclear proliferation. Michael Bloomberg Starting in 2005, under the mayoral tenure of Michael Bloomberg, New York City achieved the lowest crime rate among the ten-largest cities in the United States. Since 1991, the city has seen a continuous fifteen-year trend of decreasing crime. Neighborhoods that were once considered dangerous are now much safer. Violent crime in the city has dropped by three quarters in the twelve years ending in 2005 with the murder rate at its lowest then level since 1963 with 539 murders that year, for a murder rate of 6.58 per 100,000 people, compared to 2,245 murders in 1990. The murder rate continued to drop