ratio

Quotient of quantities of the same kind for different components within the same system.
Source:
PAC, 1996, 68, 957 (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 989
PAC, 1985, 57, 1299 (Review of plasma deposition applications: preparation of optical waveguides) on page 1309