Do you think the decade ends 12-31-09?

Here we go again. Folks are making their “best of the decade” lists. But I say the tenth year of the decade completes 12–31-10. We’ve heard the arguments starting in 1999. Let’s have it again, here. Do you think a new decade begins or ends on the multiples of 10? In other words, do you count the year following the birth of Christ as year 0 or year 1?