In economic statistics, capacity utilization is normally surveyed for goods-producing industries at plant level. The results are presented as an average percentage rate by industry and economy-wide, where 100% denotes full capacity. This rate is also sometimes called the "operating rate". If the operating rate is high, this is called "full capacity", while if the operating rate is low, a situation of "excess capacity" or "surplus capacity" exists. The observed rates are often turned into indices. Capacity utilization is much more difficult to measure for service industries.