Phoenix, AZ – The number of seats in the U.S. House is fixed at 435. The allocation is reset every 10 years after the census. Last time around, Arizona's rapid growth gave it two more seats, up to the current eight. While the next census is still two years off, new figures for this year show Arizona's population is already greater than all the states with nine seats. And it even squeaked past Massachusetts which has 10 seats -- and is growing only about a tenth as fast as Arizona. In pure numerical terms, the state's population now has topped 6.5 million. That's up 2.3% from a year earlier, and close to 27% higher than at the beginning of the decade. One reason Arizona is growing so fast involves babies: Arizona's ratio of births to deaths is higher than the national average. But the real difference is that Arizona remains a magnet: more than half of the annual population growth in the last year involves people moving here from somewhere else. And, more than 23,000 of those new residents came here from another country. The Census Bureau does not ask whether people are here legally are not because it is legally irrelevant when the number of congressional seats are handed out.