The Muslim Public Affairs Council keeps a terrorism database, which it has updated in light of recent events. Bottom line:
7 out of the last 10 Al-Qaeda plots threatening the U.S. since 9/11 have been prevented with the help of Muslims.
Overall, almost 40% of all Al-Qaeda terror plots threatening the U.S since 9/11 were foiled with the assistance of Muslim communities.
The fact that the stats have altered so much so quickly is of course, an indication of how few terror plots there actually are.