The National Alliance of Public Charter Schools estimates in a new report that 2.9 million children now attend U.S. charter schools, up 14 percent from last school year.

More than 500 new charter schools opened in the 2014-2015 school year and 200 charters were closed for reasons ranging from poor academic performance to financial problems, according to the organization.

California, Florida and Texas had the largest numbers of new schools as well as the largest numbers of closures. Eighty-seven schools opened in California, for example, while 34 closed, a net gain of 53. California now has 1,184 charter schools, according to the report, with an estimated enrollment of nearly 550,000, by far the largest charter enrollment of any state.

Charter schools are publicly funded and independently run. Nationwide there are now more than 6,700 charter schools.