Table 1.

Distribution and interquartile ranges of counties and metropolitan statistical areas

	Number	25th percentile	Median	75th percentile
Segregationa	265	0.2	0.4	0.5
% Female-headed householda	935	9.6	11.6	13.8
% Less than high schoola	935	10.6	13.9	18.8
% Povertyb	935	10.6	14.3	18.2
Median Household Incomeb	935	41,462	47,566	56,628
% Unemploymentc	935	7.8	9.2	10.7
% Uninsureda	935	12.7	16.1	19.8
Violent crime clearance rate (% crimes resolved)d	911	39.7	55.3	69.3
Primary care physicians per 1,000 populatione	935	0.5	0.9	1.4
Hospitals per 1,000 populatione	935	0.008	0.02	0.03
Preventable hospitalization ratef	923	57.5	68.9	82.9

Note: Segregation is defined by the isolation index and is calculated at the MSA level; the remaining variables represent county-level percentages and rates

^aAmerican Community Survey, 2006–2010; ^bSmall Area Income Poverty Estimates, 2010; ^cBureau of Labor Statistics, 2010; ^dUniform Crime Reporting, 2008; ^eArea Resource File, 2008; ^fDartmouth Atlas of Health Care, 2003–2007