Performance calculation

Hi All,

I have scores of say, n employees and the scores are in the range of 0-100. Each employee will have a set of scores which he secured over a time period. For a selected time period, I want to know what was the “best”, “average” and “below average” score when all the employees scores are considered. For example, I want a graph which will tell like the “best score” is above 65 and the number of employees who got above 65 are so much people, average is above 40 and the number of employees in that group and the last is below average.

I created percentile25, percentile75 calculated fields to get the score cut off for best and average. Then I created another calculated field named performancemetric which compares like,
I am able to display the data in tabular form. The tabular form is like group by performancemetric and name. The value field is avgscore of that employee. It clearly shows whether an employee is best/average/worst. But what I need is the count by performancemetric. How this can be depicted in a graph?

Any help will be much appreciated