The Historical Fee Rate for a Historical CAT Assessment will be calculated by dividing the applicable Historical CAT Costs by the projected total executed equivalent share volume for all transactions in Eligible Securities for the projected Historical Recovery Period, which may range from two to five years. The fee rate for each Historical CAT Assessment will remain static throughout the actual recovery period. Note that the projected Historical Recovery Period is only used to calculate the given Historical Fee Rate; the actual recovery period may be shorter or longer depending on actual trading volumes. A Historical CAT Assessment will remain in effect until the full amount of the relevant Historical CAT Costs is collected.