Select one of your arcs, then with either the line or pencil tool, draw a line segment from each end down to the horizontal axis. This has to be one shape. Then, open the shapesheet, go to geometry section. and set the geometry.nofill cell to false. You can now fill the area bounded by your arc and the two vertical lines. If you don't mind have a line across the bottom, you could have worked your way around from one end point, down to the axis, across, and then up to the next end point making a fully enclosed shape which should automatically fill.

Do this for 2nd arc. Then select the smaller arc shape bring it to the front. Finally, select the axis, and bring them to the front.

If you don't want the lines showing around the fill, then extra step needed...duplicate each arc before making the enclosed shape. Then, do the above. In the shapesheet, set geometry.noline to true. This gets rid of the lines around the filled area. Align the arc with the shape and group (if desired).

Alternatively, draw this in Excel and import.

HTH

Wapperdude