Part of it is just that there's a large number of people every year who essentially stop donating, for one reason or another. Either they've stopped being a donor and turned into a patient, or they've moved to somewhere where we don't have clinics. We lose a lot of donors every year just for life circumstances, or because they didn't have a very positive experience donating and they don't want to come back. There's a whole lot of different reasons why people stop.
We are always recruiting new donors, all the time. We have brought in a couple of changes in the blood system. Recently, the most notable one is to actually change the amount of time between donations for women donors, because we want to make sure that we're not causing a loss of too much iron for women.