(16)To ensure the fair treatment of all trading venues across the Union that contribute data to the CTP for shares and exchange traded funds (‘ETFs’), it is crucial to clearly specify the method that the CTP for shares and ETFs should apply when calculating the amount of its revenue to be redistributed to data contributors. It is therefore necessary to further specify the minimum frequency at which the CTP for shares and ETFs should determine the relative share of, or percentage of, revenue to be redistributed per eligible trading venue. The CTP for shares and ETFs should redistribute revenues at least annually, although it may opt for a more frequent redistribution.