The improvements in South Carolina charter school laws aren't happening fast enough to keep up with the rest of the country.

The Palmetto State slipped three spots to No. 15 out of 43 states for the quality of its laws, mostly because other states took more aggressive steps forward, according to a report released this week by the National Alliance for Public Charter Schools. Eight states don't have charter school laws.

"While South Carolina's score did increase in a few areas, our legislators did not keep pace with the transformative changes going on across the country .," said Mary Carmichael, executive director of the Public Charter School Alliance of South Carolina.

The report ranks each state's charter school laws on 20 components, including quality and accountability, equitable access to funding and facilities, and no caps on charter schools' growth. The rankings were released during National School Choice Week, which started Sunday and includes more than 3,600 events across all 50 states.

South Carolina has 59 charter schools this year serving 22,384 students. Charleston County is home to 11 charter schools. The state's total public school enrollment is roughly 710,000 students.

"This annual ranking is an important barometer for measuring changes in charter school policy," said Nina Rees, president and chief executive officer of the National Alliance. "States are increasingly aware of the impact their charter school law has on providing students access to high-quality public school options and we are encouraged to see so many improving their laws."

The report recommends that South Carolina focus on ensuring equitable operational funding, as well as equitable access to capital funding and facilities. Other recommendations include accountability for those authorizing charter schools, as well as more guidelines for the expansion of charter school through multi-school charter contracts.

"The gap between us and being in the top 10 really comes down to funding," Carmichael said.

Charter school advocates are working on that issue. They want to give more charter schools access to vacant or under-utilized public school buildings, as well as secure money for the state Charter School Facilities Fund that was created in 2012 but hasn't been funded.

Carmichael said she appreciated Gov. Nikki Haley dedicating $4 million in her budget for that, which would help schools build facilities.

"They would have to repay (the money) but it would give them access to capital funds that we don't have right now," Carmichael said.

She also pointed to a bill that passed the House last April and is awaiting second reading in the Senate. The legislation would strengthen the new charter school approval process, as well as create new public alternative education charter schools.

The state's charter school law was passed in 1996, and the state made significant changes to that law in 2012. Some of those included allowing higher education institutions to approve charter schools, and permitting single-gender charter schools. The modifications were evident in the state's ranking, which jumped 13 spots last year.

Lawmakers made more changes in 2013, and those boosted the state's overall score this year six points to 147 out of 228. Still, those weren't enough to enable it to maintain its ranking.