Also: Year of occurrence. Loss payments and reserves on losses are allocated to the year in which the loss has occurred (accident year). The development of loss payments and Loss Reserves for losses which have occurred in a given accident year are monitored in time intervals (e.g. monthly, quarterly, yearly) by development year statistics until all losses are finally settled. The losses allocated to a given accident year are measured against the earned premium income of the same annual period. Statistics on an accident year basis allow the development of losses to be monitored and are therefore particularly important for underwriting decisions.