5.5 Career YPC
1998-2004 - Edge, James Jackson, Portis, McGahee, Gore, Geathers - 7 dudes in 7 years
2005 - Present - Miller, Duke, Dallas, Homer - 4 dudes in 19 years
Any dudes under 5.5 honestly aren't worth debating that much about. It's just an argument over who's the most above average