Oh and let's just end this argument now. A decade is defined by the ten digit. Meaning if they are all the same that qualifies a decade. 00, 01, 02, 03, 04, 05, 06, 07, 08, and 09 defines the last decade. This isn't debatable haha. That is how you define a decade and why we use it. It only makes perfect sense... let's not argue with logic.