“2-yr mean citedness” is the OpenAlex field summary_stats.2yr_mean_citedness (CC0): mean citations per paper over a two-year window. It is a raw bibliometric field, not a journal rating, and is not used for default ranking.
Arts and Humanities20Computer Science15Social Sciences12Agricultural and Biological Sciences7Earth and Planetary Sciences5General Works: Museums. Collectors and collecting1Science: Natural history (General)1