Utilization rates (visits per 100 person-years) and 95% confidence intervals of Emergency Hospital Services by gender, age and zone of origin. Arnau de Vilanova Hospital (Lleida, Spain),2004–2005. 1) The horizontal lines indicate the utilization rates of the Spanish-born population. 2) In the females' graphs, there are two values and confidence intervals for each zone of origin. The first indicates the overall utilization rate and the second indicates the utilization rate after excluding gynecologic and obstetric diagnoses.