That's not necessarily true. Discontinued just means they stopped making new ones, they still would have had old stock to sell so the rest of those sales wouldn't all have been in 2006.
However that said, it does look like you are right and it is overtracked.
100% agree with you, but sales would have decreased significantly from that point on. Could it have really added up to another 4 million units after that point is what I really mean to say.