Roger, M3+ would probably still pick up these swarms. Can you graph what you come up with? To see visually the swarm behavior, you'd have to plot by day (or week) rather than year. Wait, that won't work because it would hard to show both magnitude and number vs date. But, if all we (Beth) want to see is whether the energy output or number of quakes has increased, plotting by year as you suggest should do the trick.
Chris