i think there was a measurement of the number in circulation vs how often they were seen, not super scientific but there certainly are a huge number of them in

i think there was a measurement of the number in circulation vs how often they were seen, not super scientific but there certainly are a huge number of them in circulation, with little visibility, although this may just be due to their use being confined to certain areas such as casinos etc, not much point taking one to the local shop for a pint of milk.