LIkely from around the 1980s.
This is a very old method of decorating plates and other fine dishes in China, where apparently rice grains are
inserted into the wet clay prior to firing and then are disintegrated by the high heat of the kiln, leaving small
rice-shaped holes behind. These are then glazed in along with the rest of the piece, and leave translucent holes in the bowl itself,
which is very lovely when seen with the light shining through.
Rice porcelain is considered lucky in Chinese culture.