I also want to offer an idea for icons. When the reduce a picture, the image itself is spoiled, but you can see him.
Whatever the image, it should have the following colors: green, blue and red.

Green is for the newbie members.
Blue is for workers.
Red for professionals.




Next, when you hover over the icon, it will be written how many reports were from.

This is original picture.


I found many more icons that would match this work.