it's because as the years roll on there's more people who are old enough to play it (or nearly old enough lol)
...but wait a minute, you may want to check those records, because the release day went wonky, so do pre-orders in the last 3-4 days count as pre-orders?
The game is out and playable according to many people, the servers are up. It just makes a mockery of the whole release date in general.
If you count sales of a game for 1 week AFTER it is available and playable then you'll need to re-think these records.