The rich keep getting richer in New Jersey and the poor aren't keeping pace, new data shows.

Income inequality in New Jersey, or the gap between the rich and poor, now ranks 12th-highest in the nation, according to the latest 2012-2016 Census data. It's getting worse in 14 of the 21 counties, with the other seven remaining steady.

The gap is most pronounced in Essex County. Home to both Millburn, which has one of the state's highest median household incomes at $190,625, and Newark, which has one of the state's lowest at $33,025, Essex is one of the most economically segregated places in the country.

The Census calculates income inequality using a measure called the Gini index, which assigns a value between 0, which would mean complete equality, and 1. The closer a score is to 1, the more wealth is concentrated among fewer people and the bigger the income inequality.

As a state, New Jersey boasts a score of 0.4782. That's slightly higher than the last five-year period, 2007 to 2011, measured by the Census, but lower than the national average of 0.4804 over the last 10 years.

With a score of 0.5478, Essex County has the worst income inequality of all New Jersey counties. In fact, Essex ranks 19th in highest income inequality out of all counties in the nation, according to Census data.

The state with the highest income disparity is New York with a Gini score of 0.5102, followed by Connecticut and Louisiana.

Carla Astudillo may be reached at castudillo@njadvancemedia.com. Follow her on Twitter @carla_astudi. Find her on Facebook.