Disparities in health outcomes across regions are a central concern in public health and epidemiology. Health disparities research often links differences in health outcomes to other factors like count frequency. Choropleth maps of health outcome rates showing the geographical distribution of health outcomes need to study. We downloaded data from the website of Taiwan government-run National Health Insurance Administration(NHIA) to illustrate the use of cumulative frequency map legends(CFML) for visualizing how the health events are distributed in relation to count frequency. Three types of therapeutic duplication of medication in patients with high blood pressure, high blood sugar, and high blood lipids among counties and cities in Taiwan were applied to present choropleth maps on Google Maps. We applied CFML to complement the choropleth maps and verified that the CFML should be revealed and reported to readers with respect to the choropleth maps. Inconsistent on ranking results across drug types across counties/cities in Taiwan was evident. Online dynamic dashboards of elder populations around the island were also demonstrated using the choropleth maps. CFML can be useful supplements for choropleth maps and effectively to communicate the proportion of areas and count frequency to readers in the future.