Want to stay safe? Head to Maine and avoid Louisiana as America's most violent states revealed

For those looking for peace, it may be wise to steer clear of Louisiana. 

So says the non-profit Institute for Economics and Peace, which has released its U.S. peace index for the second-straight year. 

24/7 Wall St. reported that the rankings were compiled based on five categories, including violent crime, amount of law enforcement and the ability to obtain small arms.

IEP founder Steve Killelea told 24/7 Wall St.: 'In perfect states, there'd be no crime, therefore you’d have no need for police, nor would you lock anyone up.'

Mr Killelea said that because peace is not an exact science, the organisation’s findings are based on several factors.

Killelea told 247WallSt.com: 'I don’t think there’s a single silver bullet which creates peace. I think it’s multi-dimensional and really complex. So, on that basis, we've pulled out the correlations.'

Violent: Louisiana was marred by its murder rate, which - at 11.2 per 100,000 people - is the highest among each of the 50 states

Louisiana was marred by its murder rate, which - at 11.2 per 100,000 people - is the highest among each of the 50 states.

Maine, which has been crowned the most peaceful state in the nation, had the lowest levels of violent crime, incarceration and police officers.

A state’s education system also comes into play in the IEP data, with education appearing to have the most impact on where a particular state wound up on the list.

Tranquil: Maine, named the most peaceful state in the nation, had the lowest levels of violent crime, incarceration and police officers

High school graduation rates in particular had a striking effect on that state's rank in the peace index.

Killellea told the 24/7 Wall St.: 'It is not so much the quality of education that matters for peace, but that states keep children in school and off the streets.'

Overall the United States is more peaceful now than at any time in the past 20 years, MSNBC reported.

But violence still cost the economy at least $460 billion in 2010, both through direct costs and lost productivity.

The IEP, which is based in Australia, first released the U.S. peace rankings last year.