You can use the chart to judge changes in your fitness over time compared to others using Xert.
Keep in mind there are top cyclists in the mix that generate numbers most of us will never come close to achieving by a wide margin. So the bar is set very high at 100%.
I pay more attention to the shape of the chart to determine strengths or weaknesses within my power curve. That will show up as an irregular square or star shape rather than a round circle.
The two circular charts to the left of the spider measure your personal growth over time compared to the population group selected.
As to which athlete type to select, GC Specialist is considered a good place to start.
You can always change athlete type at any time to affect which workouts are recommended.
If you are a new to Xert this thread has lots of tips to consider –
Beginner questions - Support - Xert Community Forum (xertonline.com)