On Wednesday, the Census released its 2005 estimates for county populations across the country. You can read yesterday’s Post coverage, which focused on the rapid growth in the region’s exurbs, here. What we’re excited about, however, is the ability to put together metropolitan population numbers for Washington at the halfway point between the 2000 and 2010 census.

Ok, first what we already know: the District is still losing population (D.C.’s estimate actually came out a few months ago, along with the states). Washington lost an additional 4,000 from last year (which put it at 550,521), but, as we’ve noted here, there is evidence that the trend toward population decline here will soon be halted and reversed.

Elsewhere, there’s nothing to talk about except growth. The central metropolitan area, which includes the District, the immediate suburban counties in Virginia and Maryland, and Alexandria, grew by 128,527 people over the last five years (to a total of 3,694,803), for a ten year growth rate of 7.2 percent. That’s a little slower than the pace achieved from 1990 to 2000 (in percentage and absolute terms), no doubt because much of the central area of the region is pretty damn full.

The greater Washington area, as defined by the census, which includes commuting suburbs south to Fredericksburg and west to West Virginia, grew at a faster pace (in absolute and percentage terms) than it did during the 90s and now stands 5,371,227 strong. In the past five years, the region has added almost half a million people for a ten year growth rate of 18.2 percent (in the 90s the same area grew 16.6 percent). On a percentage basis, Washington’s growth rivals are all southern and western cities; Washington is growing relatively faster than New York, Los Angeles, and Chicago, and is coming close to growing faster than Chicago in absolute terms (indeed, it is likely that is so).