All of the posts above reveal why any "average" figure is a bunch of nonsense. Think about how that number is calculated:
- Nobody does it in less than 40 hours (35 for part 141), period, since that's the minimum. So that skews the distribution right there
- Many, many pilots take some training, then stop. Several years later, take some more, then stop. Some have been almost ready for the checkride, then stopped only to restart training 20 years later, having to relearn everything.
- Many pilots (as in several posts above) do extra training just for the experience or fun of it. This, of course, raises the average, while it really doesn't reflect how much training was needed.
- Some pilots just really, really struggle for 100 hours or so, raising the average.
- The average includes all ages of students, too. Let's be honest, we typically learn slower as we age. As a CFI, I've seen this often. So maybe the 17 year old zipped through it in 40 hours, but the 70 year old took 100. Right there, the average of the two is 70, but doesn't really reflect at all how long it might take a particular student.
As others have mentioned, scheduling numerous lessons per week is the way to go.