Do this for forwards only, or just centres.
Here is a stat: NHL.com - Stats
From 2013/14 to today here are the the Top Ten 1A Centres (with their placing in 2As):
1. Getzlaf (9th)
2. Seguin (26th)
3. Crosby (4th)
4. Backstrom (1st)
5. Thornton (3rd)
6. Tavares (19th)
7. Zetterberg (13th)
8. Malkin (15th)
9. Kopitar (6th)
10. Johansen (8th)
Six of the Top Ten are in the Top Ten in 2As and only one player (Seguin) is out of the Top 20.
Seems to be a very strong connection between centers who get 1As and 2As.
I don't see any point in restricting it to centres and then looking at it over a 5 year period, as it severely restricts the number of players who can reasonably be looked at: players who have been 1Cs for the past 5 seasons. But even still, for Seguin to be 2nd in 1As and 26th in 2As among Cs along with Tavares being 6th and 19th in pretty damning in terms of the value of 2As. It confirms what I have said - it strongly measures a player's linemates as well as their PP time and if the PP revolves around them.