plot average values from "sub-domains"

"Beginner level"
Hey
I would like to plot average values (ie. concentration) obtained from "sub-regions" inside a domain as a function of the position of these "sub-regions" in my geometry (here the y axis).

I can get the averages one by one using "Derived Values" as in the example (capture01.jpg) joined; but I can't get a plot of the table as it is. Given the large number of "sub-domains" I would have hoped to avoid going via Excel or the like!
Creating an Average data set from the predefined areas didn't help, I get an error message when I try to plot values from it.

Thanks for any advice.
Eric