Correct... 2000 was the final year of the '90s and 1990 is the final year of the '80s. The fact that the year 0 doesn't exist (the term "year 0" is often used to refer to the start of the counting of years, but that doesn't make it an actual year) has confused loads of people, and I think things should have been easier if the year 0 was an actual year. A lot of historians doing research about Jesus, have the feeling that the starting of the year counting was already not correct, as they believe that Jesus was born 7 years earlier (and the birth of Jesus is what the current counting of years was based upon... hence the term B.C. (Before Christ) for the years before the year 1), so perhaps a little re-calculation is in order anyway, and one may wonder if 1 year really matters. But I guess it's not that easy, eh?