What Are the Odds?

It is early 2006, and you are asked what the probabilities are of 6 years in a row of US hurricane seasons with no landfalls of intense (Cat 3+) hurricanes. No such event had ever been observed.

What would you say? Here is what I'd have said:

1. From 1900 to 2005 there were 69 of 106 years with intense hurricane landfalls (data in graph above from NOAA).
2. That means that, based on the entire record, the odds of a single year with no such landfalls is 0.349 (i.e., 1 - (69/106)).
3. The odds of six such years in a row is thus (0.349 ^ 6) (to the sixth power)

. . . or 0.18% or 1 in 553.

What would you have said?