How New Horizons' launch date affects its arrival date

I'm looking forward to the next launch attempt for New Horizons tomorrow. I was looking at that table of launch times from spaceflightnow.com and realized that the table included another valuable column of data that I hadn't noticed before: it tells you what year New Horizons will arrive, for each of the possible launch dates. Here's a summary of that information:

I thought it was interesting to see how the dates grouped with the arrival year. Launch dates prior to February 3 get that Jupiter gravity assist; on or after February 3, it's direct to Pluto.