A base for a coin store comprises an essentially planar part for supporting a coin or coins and retaining means for retaining coins within the coin store in use, and the retaining means comprises at least one part extending essentially perpendicular to the planar part of the base. For a respective event, multiple inter-event interval pairs based on occurrence times of pairs of respective remaining events relative to an occurrence time of the respective event are memorized. The ArF excimer laser device connects to the output terminal of a magnetic pulse compression circuit and has a pair of laser discharge electrodes located within the laser chamber and a peaking capacitor connected in parallel with the pair of laser discharge electrodes. Various embodiments characterize traffic behavior at a plurality of distinct airports and traffic behavior of a selected airline, both at an airport and at distinct airports.