Table B-2. 90-Percent Confidence Intervals of Standard Errors of Estimated Percentages for Characteristics of Vacant Rental and Homeowner Housing Units: 2006 90-Percent Confidence Interval (+/-) of estimated percentage\1 1 or 2 or 5 or 10 or 15 or 20 or 25 or 99 98 95 90 85 80 75 50 Vacant rental units....... 0.1 0.2 0.3 0.3 0.4 0.5 0.5 0.6 Vacant homeowner units.... 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3 \1 A 90-percent confidence interval is a measure of an estimate's reliability. The larger the confidence interval is, in relation to the size of the estimate, the less reliable the estimate.