This paper presents new data about diabetes prevalence and illness duration from a population of patients with diabetes Type 1(43,818) and Type 2 (457,247). Unlike the usual approach that employs adjusted estimates in similar prevalence reports, this study extracts data from a large number of original clinical documents such as all the outpatient records (6,887,876) issued in Bulgaria to all the 501,065 patients with diabetics during 2018 (9.77% of all the 5,128,172 patients recorded in 2018, 4.43% male and 5.35% female). Diabetes prevalence data are described in terms of distributions of Type 1 and Type 2 diabetes over age and gender. It is mapped to an Observational Medical Outcomes Partnership Common Data Model that is publicly available. The distribution of Type 2 diabetics agrees with peak values of BMI established in related research. A major novelty in this research are the data about the diabetes illness duration. It is an essential metric for evaluating the quality of processes evolving over time. Accurate estimates are obtained for the duration measured in years of Type 1 (95% CI 10.92, 11.08) and Type 2 (95% CI 7.97, 8.02) diabetics from the Bulgarian population. The patients with diabetes Type 1 have longer diabetes duration relatively to those with Type 2. It is recommended to include this metric in official diabetes prevalence reports.