2011 NAs were included in the 2011 rankings. As fas as the worlds, I think they are not included because of #5:

A skipper may receive USF18 points in an event provided that:
1. The skipper is registered as the skipper of the boat in the event
2. The event is held in the USA, Canada, or both,
3. Event entrants are informed before racing begins that F18s will be scored separately,
4. The event authority requires all competitors competing as F18s to follow the F18 class rules,
5. The event is open to all USF18 members, and
6. The skipper is a full member in good standing of USF18 at the beginning of the event

Because the worlds is a limited entry, invitation event, I don't think it satisfies #5 above, even though for the just completed worlds every boat that wanted to go could. Not sure why more SE events aren't on the list- I see Charlotte Harbor there.