Mully, while Smith has remained steady over this time period, what about the addition of 2 new worlds. In a perfect world, at least a perfect HD world, every world would be exactly even, whenever 1 person a new person would come in. In reality, no world will ever be completely filled every season, or even in any 1 single season.
I assume the goal for Admin is for all worlds to get establish and demonstrate the ability to stay at a consistant participation level. Then slowly add a new world or 2, hoping to get that world up the same participation level in a given time period as previous worlds.
I'm sure they have a target number for the number of total coaches in a given world during any one season in order to turn a profit. I have no idea if they're at that level, above that level, or below that level in the established worlds, but the fact that Smith has remained the same since you started tracking while 3 new worlds of HD has been added is a positive thing for WIS I would think.