A new report released Thursday says the child poverty rate is on the rise in Maine. The annual ‘‘Kids Count’’ report by the Maine Children’s Alliance said 19.3 percent of Maine children under the age of 18 lived in poverty in 2011. That is up more than 1 percent from 2010, but below the national rate of 22 percent. The report showed improvements in high school graduation rates, which rose to nearly 85 percent in 2012 from about 83 percent. It also said that about 5 percent, or 14,000 Maine children, lacked health care coverage between 2009 and 2011. The national average is double that.