But when does an anniversary occur? At the beginning or the end of the year? 1986 was the first year, 1995 was the tenth year but the ASE didn't start at the beginning of 1986 so its tenth anniversary occurred in mid 1996. Or even if you don't go to that extreme 1995 was the tenth year of production, but the tenth anniversary was after the END of the year or 1996.
Precisely! In 1995, the Mint made a special set to mark the 10th year of the coins' existence. An anniversary per se is NOT an analogous concept. People celebrating their 25th wedding anniversary are celebrating the day that the 26th year of their marriage begins.