• Accident data for the year is a method of organizing the loss and risk data of an insurer or a group of insurers or in the business book in such a way that all losses associated with accidents that occur during a given calendar year and all premiums received during a given calendar year are compared. the same calendar year. . Thus, regardless of the individual insurance periods and regardless of when a loss is reported or paid out, the 2015 accident data will include all insurance premiums earned during 2015 and will include all losses that occurred in 2015. annual data in their rate suitability analysis. For example, the Compensatory Loss Development Factors (LDFs) published by the National Council for Compensation Insurance (NCCI) are developed based on data from the year of the accident.