Good point. For so long, we (and all the reputable crowd calendar makers and Disney touring guide publishers) have measured WDW "crowds" in terms of attraction wait times. It's a hard habit to break, and I think it will be some time before guests change their mindset to understand that when there are fewer people in the parks, Disney is purposely reducing staff, ride capacity, and hours, in order to keep wait times (and the perceived need to buy G+) as steady as possible. As a result, there's no way to measure (other than eye-balling and guessing from the crowdedness of common areas, or extrapolating knowledge of historical crowd levels) whether park attendance is rising, falling, or staying the same. Nor does it really matter to the average guest, since WDW is doing its best to ensure that even if you visit during a "low crowd" time, you're unlikely to see much benefit from that choice (or at least, far less benefit than you used to get), in terms of attraction wait times.