Texas Population Data Sources and Updates

The population data maintained by staff of the DSHS Center for Health Statistics originate from different sources:

• Census Data - 1990 & 2000

Once released from the Texas State Data Center, these population figures are final, and will not ordinarily be replaced by future sets of data. At CHS, the TxSDC estimates remain the most stable and dependable population data for most purposes. When new estimates become available, usually in December of each year for the mid- year (July 1) population of the preceeding year, they replace the projected population data.

• Estimates - currently 2001-2009

Once released from the Texas State Data Center, these population figures are final, and will not ordinarily be replaced by future sets of data. At CHS, the TxSDC estimates remain the most stable and dependable population data for most purposes. When new estimates become available, usually in December of each year for the mid- year (July 1) population of the preceeding year, they replace the projected population data. Details of methodology may be obtained from the Population Estimates Program web pages at the Texas State Data Center.

• Projections - currently 2010-2040

The Texas State Data Center prepares population projections for Texas counties every two years. The current projections were released in February 2009 and cover the period 2001 through 2040. A number of projection "scenarios" are available, differing only in the strength of the net migration that is assumed to occur across the entire projection period. The Center for Health Statistics selects among these options the projection scenario recommended for short term planning of less than 10 years. The Center for Health Statistics can provide assistance in choosing a projection scenario for population planning beyond 10 years. The current projections reflect the "2000-2007 scenario", indicating that the net migration assumptions utilize migration patterns from the 2000-2007 post-censal period. A concise statement of the methodology underlying the projected data appears on the website of the Population Projections Program at the Texas State Data Center.

• Estimates - 1991-1999

Prepared by staff of the DSHS Center for Health Statistics using age-race-sex specific interpolation at the county level to produce a series of smoothly varying population figures. These data do not provide estimates for single year of age beyond age 74, unlike population figures for 2000 and beyond, where single year of age detail may be obtained through age 84. However, five year age group data for ages 75-79 and 80-84 can be extracted from the database for 1991-1999. No plans are in place to replace population data for any of these years.