I think there might be a glitch in the scoring here.

http://moowrap.net/top_hosts.php

Go to the link a hit tasks for any computer on the list.

Then click on the finished and valid tasks

Run time under 5 min and score of over 6.000. Okkkkkkkkkkk

No wonder a lot of them have over 1/2 million recent avg. credit. on one machine.