[Clubber]

Yes, I was thinking about that earlier. I would suggest lowering the strength of ratings the older they get when calculating the average, so:

  This year's average is 50% of total rating
  Last year's average is 30% of total rating
  Previous year's average is 10% of total rating
  All prior years' average is remaining 10% of total rating

Instead of years, it could be a rolling year, so average of last 52 weeks would be 50%, prior week 53-104 would be 30%, etc.