Complete year-by-year NBA Draft History can be found here.
The stats here include the 2013/14 NBA season.
Only the past 25 NBA drafts are included in the highest, lowest and median rankings.
Median PER (or other stat) simply denotes the mid-point PER value when observing the entire list of players drafted at this spot. It attempts to portray a realistic expectation of what a team can expect to draft at this spot based on historical outcomes.
If a player's position is G/F he is included in both the guards and forwards for the positional breakdown.
Win shares is a cumulative statistic so recent draft picks will obviously have lower totals.
Win Shares takes into account offensive and defensive rating, usage rate, and team wins. For a definition and more thorough explanation of Win Shares, click here.
Anthony Davis - 2011 McDonald's All-American Game (Interview & Practice Highlights)