This Wire-to-Insulation Ratios data set compares the various ratios of wire cross-sectional area to the insulation's cross-sectional area for various standard gauges of copper wire.
The AWG field (column) defines the standard gauge of the wire.
The field called Bare_wire_area_cm2 defines the cross-sectional are of the copper conductor alone.
The other columns define the ration of copper to insulation's cross-sectional areas for Single, Heavy, Triple and Quad insulation thicknesses.