Camden and Gloucester Counties both saw an increase in the percentage of children living in poverty from 2010 to 2011, while in Burlington County, median family income dropped and more than half of the county's families paid more than the recommended 30 percent of income for housing, according to a new study released Wednesday.

On the plus side, Burlington County's infant mortality rate dropped, and median incomes in Camden and Gloucester Counties rose.

Those are among the findings of "New Jersey Kids Count," the latest report on child and family well-being in the annual series issued by Advocates for Children of New Jersey.

"While the rankings shift every year, we see certain trends across most counties, including increasing child poverty, unemployment, and high housing costs," said Cecilia Zalkind, executive director of Advocates for Children. "These statistics should be used to inform local, county, and state leaders, as well as community organizations, in their efforts to improve the well-being of all New Jersey children."

From 2007 to 2011, the percentage of the state's children considered low income - below 200 percent of the poverty level - increased by nearly 20 percent. Thirty-one percent of the state's children fit in that category.

For the same four-year period, the percentage of very poor children - 50 percent of poverty level, or $11,175 for a family of four - rose by 40 percent.

From 2005-07 to 2009-11, the percentage of New Jersey households that did not have enough food also rose 40 percent, according to the U.S. Department of Agriculture surveys, compared with 34 percent of all United States households. And from 2008 to 2012, the number of children getting food stamps rose 80 percent.

Median income for families with children in New Jersey fell from $82,555 in 2007 to a five-year low of $81,983 in 2011. That same year, 27 percent of New Jersey children were living in families in which no parent had full-time, year-round employment.

Each of the state's 21 counties is given an overall ranking. Burlington County rose to eighth from 11th in last year's report. Camden County moved up to 16th from 19th. Gloucester County held steady at 10th.

The county that scored the best was Hunterdon County. In last place was Salem County.