American Community Survey (ACS) estimates that contain extreme values (e.g. 0% or 100%) or have a wide confidence interval are likely to be found in small geographies, small populations, or households that have a small sample size. Estimates based on small sample sizes are likely to be less reliable and widely fluctuate between time periods. Some census places (cities/towns), census tracts, and zip code tabulated areas (ZCTAs) are among the smallest geographies that have data available from the American Community Survey. Exercise caution when using or interpreting these estimates.
Click here for more information on ACS estimates and margins of error.