They'll let you defer one year, so I'd get on the list for this fall. They send a notice out in November(I think. Maybe early Dec) letting you know your number on the list. We started out in the mid 200s and were down to very low 100s after two seasons. Slightly more than a year due to getting in the list in Sept.
Obviously, if you're willing to do 'shoulder season' trips, you'll get on faster.