Perhaps those sky-high housing prices are finally having some effect on growth. For whatever reason, Los Angeles County saw a population increase of only 6,900 between July of 2005 and July of 2006. The annual average going back the previous five years was 69,500, so we're looking at a significant slowdown (OC and Ventura also showed declines in population growth). The one area of Socal that keeps booming is Riverside-San Bernardino, which showed a gain of 116,200 between 2005 and 2006, according to Census numbers (and analyzed by the L.A. County Economic Development Corp. That's fifth in the nation, behind Houston, Dallas, Atlanta and Phoenix. Of course, the home price theory only gets you so far, considering that between 2001 and 2006, the median resale price of a home in Riverside-San Bernardino went from $159,760 to $409,090.