AUGUSTA, Maine — A state-by-state assessment measuring crime, guns and other factors lists Maine as the most peaceful state.

The nonpartisan, independent Institute for Economics and Peace released its annual peace index on Tuesday. The ranking is based on analysis of homicide, violent crime, policing, incarceration rates and availability of small arms data.

See the index here.

Overall, it finds the Northeast to be America’s most peaceful region with the lowest homicide, violent crime and incarceration rates in the country. The South is the least peaceful region with the highest homicide, violent crime, and incarceration rates, as well as the highest prevalence of gun ownership, and the second highest police employee rate.

Maine is America’s most peaceful state with recorded reductions in the homicide and incarceration rates as well as the number of police employees. Louisiana ranked last for the 11th year in a row.

The survey, first issued in 1991, finds that the United States improved in all five categories over 2011, including a 3.2 percent drop in homicides and a 5.5 percent reduction in violent crimes.