4767e3a6___Documentation__8_4__pg_stats__Description
[Name] most_common_freqs [Type] real[] [Description] 
A list of the frequencies of the most common values or elements, i.e., number of occurrences of each divided by total number of rows. (NULL when most_common_vals is.) For some datatypes such as tsvector, it can also store some additional information, making it longer than the most_common_vals array.
PostgreSQL: Documentation: 8.4: pg_stats