Over the last few weeks, why has Avast's zero day protection fallen so much?

Avast used to consistently be in top 3 (over a year period it is still #1), with a zero-day prevention rate of about 80-95% every day on this site that does a running daily test of zero-day protection of pretty much all the antivirus programs:

http://www.shadowserver.org/wiki/pmwiki.php/AV/VirusDailyStats

But over the last few weeks it has fallen to the 30-50% range in protection and toward bottom of the long list of programs tested.

You can see weekly, monthly, 90, 180 days, 1 year results and see the slide.

Anyone know what was changed in Avast over the last few weeks?

Lol…And you honestly believe some bogus site such as what you link to? Why don’t you check out a real legit site such as AV Comparatives, VB 100 and AV-Test.org. Come back to me after you check those real sites out.

As I wrote, Avast had been top on that site for a while. Those other tests are good, but the one I cited does a daily test, while the other are quarterly at best. I use Avast - I am not knocking it. I just want to know if something recently changed.

http://westcoastlabs.com/realTimeTesting/article/?articleID=1

That is 2011 data, per that page.