What is the definition of the "solar mixing ratio"? What is the definition of the "solar mixing ratio"?

Specifically, I'd like to know why the ratio of H2 and He is 0.84 and 0.16 at the "solar mixing ratio" as shown in Table I in The Galileo Mission.
An answer which explains it possibly, but remains speculation as I don't find the term explained:

Taking the pristine abundance of atoms, from which the sun formed (thus solar mixing) gives you a ratio of H and He atoms of 92% hydrogen to 8% helium. Converting that to the place and phase where we have molecular hydrogen (H2), gives a molecular mixing ratio of 83% hydrogen (H2) and 13% helium (He) - which is pretty close to the values given there. They probably use another source with slightly different numbers for the pristine elemental abundances than this wikipedia article.

Thus I consider it likely that they compare molecular abundances. They compare the abundances or ratios you would see, if you took the pre-solar nebular without any chemical segregation and formed the giant planets with the one measured by their spectrometers when actually looking at the atmospheres of the planets.