Why are the scores lowering?

[David (PassMark)]

The numbers are averages. So they can vary up and down slightly as more results are added to the average. Especially when there are a small number of samples.

[FlightTribe]

Just noticed on the benchmark page that the scores for everything are getting lower.
Seems weird.
My card was just over 3000 and now it's just under.... I don't think cards are getting worse over time are they? :P