Arizona expects a 5 percent increase in state tax collections in fiscal 2013, one of just nine states where revenues are projected to rise more than 5 percent, a new report says.

Experts and state officials said the increase reflects the general improvement in the state's economy and that the 5.1 percent increase may actually be a conservative estimate.

A spokesman for Gov. Jan Brewer said the prediction by the National Conference of State Legislatures is "very much in line" with the state's earlier estimate of a 5.5 percent revenue increase in fiscal 2013. "We expect it to be even better than what was predicted," said Matthew Benson.

Dennis Hoffman, director of the L. William Seidman Research Institute at the W.P. Carey School of Business, said Arizona's revenue growth is not completely surprising.

"The state's economic situation over the last four to five years was depressed, but in the last two years, we have seen increasing signs of growth coming off of this depressed level," Hoffman said.