Radial Histogram
Radial Histogram (also known as Circular Histogram, Circular Bar Chart, Angular Histogram, Polar Histogram) is a variation of a bar chart where every bar is displayed along a circle. Compared to traditional linear bar charts this results in more eye-catchy visualizations with an ability to display more bars in the same space. On the negative side, these charts are harder to read and make it difficult to compare values at distant locations along the axis.
Demo source