(14)The calculation of natural catastrophe risk with the standard formula should account for the nature, scale and complexity of the exposure of the insurance or reinsurance undertakings to that risk. The calculation of natural catastrophe risk with the standard formula requires that insurance and reinsurance undertakings map their sum insured in risk zones. Not all insurance and reinsurance undertakings have the information on risk zone level required for that calculation in their internal systems, and for those undertakings it may be costly to produce this information. Those undertakings should therefore be able to base their calculation on groupings of risk zones where such grouping is well substantiated and proportionate to the exposure.