The property damage measure is further disaggregated into four bands depending on the measured scope of the property damage inflicted by one incident. These bandings are shown in the table below, whereby incidents causing less than US$1 million are accorded a weight of 1, between $1 million and $1 billion, and more than $1 billion. A great majority of incidents are coded in the GTD as an 'unknown' level of property damage, thus scoring nil, with 'catastrophic' events being extremely rare.