year-before period; corresponding period of previous year; same period a year ago
前年同期比で増収だ。
Revenue is up year-on-year.
売上は前年同期と比べて増えた。
Sales increased compared to the same period last year.
利益が前年同期を大幅に下回るのは初めてだ。
It's the first time profits fell significantly below the same period last year.