Accident experience in relation to a base unit of measurement, such as motor vehicle rail/road and aircraft accidents: for example, number of accidents compared to miles operated or passengers carried, ‘number of deaths per 2,000,000 miles travelled,’ and so on. Although an injury rate is more commonly used, occupational accident experience can be expressed as the number of accidents per 100,000 employee-days worked, per 100 employees, or per employee-year (200 working days).