year-on-year change; relative change from previous year
Used in business, economics, and statistics to compare a figure with the same period one year earlier. Often appears in reports as a ratio or percentage.
The year-on-year change in sales was a 5% increase.
This indicator needs to be viewed in terms of year-on-year change.
前年比 also means 'compared to the previous year' but is slightly less formal and more common in everyday business contexts. 対前年比 is more explicit and often used in official statistics.
前年同期比 specifically compares the same period (e.g., same quarter or month) of the previous year, while 対前年比 can refer to any year-on-year comparison.
Compound of 対 (たい, 'versus' or 'compared to'), 前年 (ぜんねん, 'previous year'), and 比 (ひ, 'ratio' or 'comparison').