Membership
Most of us would agree that membership is pretty important to Scouting. Does that make you wonder why the membership criterion for the National Quality Unit Award is not one of the required ones? There's a reason for that, which I'll get to momentarily.
First let's address the standard represented by the criterion; at first glance it seems like a pretty low standard - equal to or greater than, some would say, is way to vague. You would think that a quality unit should be able to show some growth, but the quality of a unit is not the only thing that drives membership growth. There are a lot of things that come into play; some of them are completely beyond the control of the troop.
Some troops manage to present a quality program, and conduct quality activities; yet don't experience a growth in membership. Sometimes the troop even plans it that way. For instance, if the troop gets too big, the troop leaders may decide to slow its growth. They may even decide to split into two distinct units, complete with distinct charters. That of course results in a loss of membership, but it's a loss due to quality oddly enough. Whatever the dynamics involved, membership growth is not as reliable an indicator as other elements.
Growth in membership can be the direct result of a troop's program, but it could also be the direct result of a sudden growth in the community's population, a larger number of youth in a particular age group, or even a lack of a program in another troop. You'll notice that the other criteria for the award do not have such an outside influence.
This influence of outside factors is one reason the membership criterion is not a required one. The BSA does an incredible amount of statistical analysis in two primary areas. The first is advancement. The second is membership and retention. They study every number they can get to find out why boys join Scouting, why they join a particular troop, and what keeps them in Scouting or drives them away. All of that analysis tells them that there are many factors involved, and the BSA, the local council, or the units cannot control some of those factors. Trained leadership and an effective program certainly contribute to membership growth and retention, but they don't have much of an effect if there are no boys to attract.
Your goal, obviously, should be to meet the criterion and renew your charter with an equal or greater number of Scouts. That should be your goal if that's the right thing for your troop. If the troop already has 75 and your meeting room is like a sardine can, you might set a different goal. If you're at 40 and you don't think you can handle many more, you'll probably set a different goal. You may even know about a community dynamic that will have an impact on whatever goal you set. The point is, whatever goal you set should reflect your unique situation - and be realistic.