Life expectancy is considered a measure of progress in a society. In the United States, with life expectancy steadily rising since at least 1900, there is likely an expectation that people will live increasingly longer lives.

In 2015, however, the first drop in U.S. life expectancy was reported since 1993. The typical American born in 2015 could expect to live 78.8 years, down slightly from 78.9 years in 2014. Furthermore, there is great variation among cities in the concentration of certain advantages that can help the population live longer, healthier lives. In some U.S. cities, residents enjoy among the highest life expectancy in the world.

To highlight variations in life expectancy by geography, even within a state, 24/7 Wall St. listed the city with the longest life expectancy at birth in every state. Looking at all U.S. metro areas, life expectancy is highest in Naples-Immokalee-Marco Island, Florida, at 83.4 years. In contrast, life expectancy at birth in Gadsden, Alabama is nearly 10 years shorter, at 73.9 years.

Click here to see city with the longest life expectancy in every state.

The association between wealth and longevity is not fully understood but well established. For a variety of reasons, including access to higher quality medical care, less financial-related stress, and living in better-served high income areas, wealthier individuals tend to be healthier, and poorer individuals less healthy.

Adults living in poverty are nearly five times more likely to report being in poor or fair health than more affluent American adults. According to a 2016 study published in the Journal of the American Medical Association, the richest 1% of Americans live on average nearly 15 years longer than the poorest 1%.

The cities on this list tend to have higher household incomes and a smaller share of residents living in poverty than metro areas with shorter life expectancies. This is also the case when comparing each metro area to the respective state poverty rates — the cities with the longest life expectancies have lower poverty rates than the state as a whole. In the national context, poverty rates in 21 of the cities on this list are lower than the national poverty rate of 15.5%.

Another common trend among the cities with the longest life expectancy in their state is the tendency to report more healthy behaviors than among cities with shorter life expectancies. In cities with longer life expectancies, exercise and healthy eating habits contribute to lower obesity rates. Obesity is associated with higher risk of life-shortening diseases. Obesity rates in the majority of cities with the longest life expectancy in their state are lower than the state and national obesity rates.

Similarly, smoking rates in these metro areas almost always trail the statewide adult smoking rates. And compared to the 18% of adults who report a smoking habit nationwide, only 12 cities report a higher smoking rate.

To determine the metropolitan areas in each state where people live the longest, 24/7 Wall St. reviewed 2014 county-level life expectancy at birth figures provided by the Institute for Health Metrics and Evaluation (IHME), a global research center affiliated with the University of Washington. The data came from the report, “United States Life Expectancy Estimates by County 1985-2014.” Using death records data from the National Center for Health Statistics, researchers estimated age-specific mortality rates for U.S. counties from 1985 to 2014.

To obtain metro area life expectancy estimates, we mapped the counties to their corresponding metro areas and calculated the average life expectancy across all counties in a given metro area. County estimates were weighted by 5-year population figures from the 2014 American Community Survey (ACS)

Metro-level median household income came from the U.S. Census Bureau’s 2016 American Community Survey. Obesity rates came from County Health Rankings & Roadmaps program, a collaboration between the Robert Wood Johnson Foundation and the University of Wisconsin Population Health Institute.