This horizontal bar graph sample shows distribution of European Programme for Intervention Epidemiology Training (EPIET) fellows by country of origin in 1995-2005. It was designed on the base of the bar chart from the website of the Field Epidemiology Manual (FEM) Wiki, the European Programme for Intervention Epidemiology Training (EPIET).
"The simplest bar graph displays data from a table with one variable. Each bar represents one category. Bar graphs can be organised horizontally or vertically. Vertical bars differ from histograms since they are separated by a space. The height of the bar is proportional to the number of events (e.g. cases) in the category, nevertheless the surface is not always proportional to the width of the category on the x-axis (e.g. different width of age groups). If there is a logical order between categories it should be respected. Otherwise categories can be organised along decreasing or increasing values of respective bars. Variables in a bar graph can be discrete (e.g. sex, region, race) or continuous (e.g. age) but organised in categories (e.g. age groups). The x axis does not need to be continuous." [wiki.ecdc.europa.eu/fem/w/wiki/bar-graphs]
The bar chart example "EPIET fellows by country of origin" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Bar Graphs solution from the Graphs and Charts area of ConceptDraw Solution Park.