Thank you for those illuminating comments, Tim! :-)

Of course, both the number of models and the size of editions dictate supply. In looking at Graph #6 it seems clear that larger edition size alone has not hurt retirement age. Comparing Graph #2 with Graph #4 you can see that in the most recent quarters there was about a 12% increase from the prior peak in the number of models not yet retired, but about a 35% increase in the number of units not retired. That's a lot of lighthouses that ain't ripe yet. Better hold off on the spring plantin' for a spell.