The 1.1 percent increase last year was about the same growth rate as in 2007. The worsening economy is clearly at play, whether it's the slowdown in the rate of illegal immigration or the foreclosure problems being felt in formerly high-growth areas like the Inland Empire. Riverside County grew by 1.4 percent in 2008, compared with 2.4 percent the year before. California has a population of 38.3 million. These numbers are potentially important in everything from traffic congestion to the amount of federal money coming into the state. (LAT)