PHOENIX — The growth in wagering at Arizona reservation casinos appears to be slowing.

 New figures in a study being released this morning show the tribes took in more than $2 billion in gaming revenues in 2007.

 That is 4.9 percent more than the prior year.

 And, using some rough projections, that translates out to total handle — the amount of money being wagered — somewhere in the $10 billion range.

 But Alan Meister, who prepared the Indian Gaming Industry Report for Casino City Press, noted that Arizona managed to post a 13. percent increase between 2005 and 2006, and 13.8 percent the year before.

 Meister, an economist with Analysis Group, said some of the slowdown in Arizona is reflective of the national economy.

 The figures, however, show that the situation in this state may be a bit different than elsewhere. Arizona’s year-over-year growth for the two prior years was the 11th highest in the nation; for 2007 it managed only 17th.

 And there are indications that things are getting worse this year: Recently released figures from the Arizona Gamin Department show the amount of revenue the tribes are sharing wit the state actually declined in the second quarter of this year.

 Meister’s figures are one key indicator of how much reservation casinos are taking in, as individual tribes do not public disclose their revenues. In fact, the deal they have with th state requires those figures to be disclosed only to the Gaming Department which monitors their activities, though there is one public report each fiscal year of total reported gaming revenues for all tribes combined.

 But Meister, who has been studying the gaming industry for years, has developed both some confidential sources as well as models h has used for six prior annual reports.

 That $2 billion figure represents the amount wagered in slot machines, video poker, blackjack and poker, minus what is paid out.

 The pacts the tribes have with the state let them keep no more than 20 percent of what is wagered on slot machines, 17 percent for video poker and 25 percent for keno. So the real wagering figure could be closer to $10 billion — or more than 1,500 for every man, woman and child in the state — though some of that may be people simply plowing their winnings back into the same machines or games.

 Wendell Long, chief executive of Sol Casinos, operated by th Pascua Yaqui Tribe, said the year-over-year increase of 4. percent should not come as a surprise.

 “It’s standard business cycle,’’ he said. Long said that tribal gaming, which is less than two decades old in Arizona, grew rapidly.

 “And now it’s leveling off,’’ Long said. “You can’t continue on ... with even 15 percent growth forever.’’

 And with the amount being wagered now so large, Long said even  5 percent increase is a lot of dollars.

 Meister said one factor that may be affecting Arizona gaming has been the cap on the number of gaming devices any tribe ca operate. That number ranges from 475 to 1,400, depending o tribal population.

 He said that limit, made part of the gaming compacts each tribe had to sign with the state, “artificially restricts the supply o Indian gaming.’’

 That problem, however, may be alleviated: Those 2003 gamin compacts have a clause which allows the number of machines t increase every five years. For the largest tribes that figure no is 1,666.

 And that’s not really the cap: Those gaming compacts also allow tribes to buy the rights to operate more devices from other tribes which choose not to have gaming, or which have only limited operations. That can add another 1,020 for the two largest tribes, the Tohono O’odham Nation and the Gila Rive Indian Community.

 The result was that, at last count, the Gila River tribe was operating 2,184 slot machines at three casinos; the Tohono O’odham had 1,865.

 That five-year review also is increasing the total number of tables games allowed statewide — blackjack and poker — fro 2,775 to 3,318.

 Long, however, said he doesn’t believe that’s an issue.

 What is becoming one, he said, is the economy, pointing to th figures from April through June this year — not part of

 Meister’s latest report — which show an actual decline i gaming. That, he said, is going to require tribes to respond.

 “We have to concentrate more on our core clientele now, making sure they’re happy, making sure that they continue to come in,’’

 Long said What it also means, he said, is watching expenses: Long said  4.9 percent increase in revenues means a virtually flat bottom line for tribes, what with salary increases, utilities and other costs.

 Any slowing of tribal gaming has a direct effect not only on th tribes but also various state and local services.

 The deal the tribes all have signed require them to share their profits. Much of that goes into aid for education, wit additional funds for trauma and emergency services, tourism, wildlife conservation, and treatment for problem gamblers.

 Since the tribes have been making those payments in 2003, total revenue sharing has topped $430 million.