The greatest concentration of national treasures were so named in the decade immediately after the promulgation of the Law for the Protection of Cultural Properties, from 1950 to 1960; subsequent to 1960, designations have been limited to a few each year.
国宝は文化財保護法施行直後の1950年代から1960年代に集中的に指定され、以降は年に数件の指定に留まっている。