Note how the icons above have both shape and colour so you can differentiate between them even if you are colour blind. This is best practice.
You can also change the default formatting to work on the hard coded number settings that you specify. In the example below I have changed the settings to work on absolute numbers instead of percentages (note the changes in the highlighted boxes). Also note that I have set the minimum and maximum numbers shown as 1 and 2. To do this, simply delete the value in these boxes. Thanks to Chris Webb for finally helping me understand how this works.
It’s easy to go overboard with this, but I’m happy to see conditional formatted icons in place; done right, you can pack a lot of information into a small space with them.