noun
year-on-year decline; fall below the previous year's level
Used in economic or statistical contexts when a figure (sales, production, etc.) drops below the same period of the previous year.
今年の売上高は前年割れとなった。
This year's sales fell below the previous year's level.
輸出が3か月連続で前年
Exports declined year-on-year for three consecutive months.