This data product consists of a single ASCII file
containing values and their uncertainties for 32 abundance ratios of
various pairs of isotopes of 13 chemical elements (C, O, Ne, Mg, Al,
Si, Ti, V, Cr, Mn, Fe, Co, Ni). Between this data product and a
companion catalog with isotopic fractions, isotopic composition
information is given for 21 chemical elements. The ratios are based
on 1978-1981 observations of ~50-500 MeV/n cosmic rays by the U.
Chicago cosmic ray experiment on ISEE 3. Each of the ratios is
linked in the ASCII file to the publication where its derivation is
discussed.