If you have "replaced" your sails, obviously the numbers will be out of wack.-Don't report what you know to be bad data. But if you bought your replacement sails new from Hobie, the sail purchase date would be helpful. If there are blocks of numbers given to Europe, chances are few of those boats will be in the U.S.-It will just cause a 'jump-gap' in the numbers; not a problem.

If your sails are original to the boat, that is the best data. What we're are actually doing is 'dating' the sails, not the hulls. That does not make the information any less interesting.