What an odd collection of years. Because I'm assuming the dates are inclusive, it is a 15-year span, but there are no anniversaries of really major events in the team's history. From 1987-2001, the Dragons won two Central League pennants, but didn't win the Japan Series. They moved stadiums in the middle of that period, but didn't change locations. (See the discussion in the comments.) Note that BBM has issued two Dragons anniversary sets (70th-2006 and 75th-2011). As far as the Legends series go, this is the third set - as NPB Card Guy points out below, there are Giants Legends and Tigers Legends sets.
I count an autograph checklist of 52 players, ranging from 30-120 copies each. The cards have horizontal layouts and use the water-spot blue background behind the sticker autographs and player photos.
Six-card packs cost 400 yen, with 20 packs per box. Despite being marketed as a 2014 set, this came out in December of 2013.