You completely side stepped my point. If you count the total number of terrorist attacks on U.S. soil between 1980 and 2005 - including 9/11 - Islamic extremists are responsible for only 6% of them.
One highly damaging attack doesn't suddenly mean just about all terrorists are Muslim. It's factually incorrect. 9/11 is a gigantic outlier and completely skews the data on the number of deaths caused by Islamic extremists on U.S. soil. 9/11 resulted in just under 3000 deaths. The second most deadly attack was the Oklahoma City bombing, with 168 deaths. 9/11 resulted in nearly 20 times the number of fatalities as the second largest terrorist attack.
Excluding 9/11, there were a total of 527 fatalities due to terrorist attacks on U.S. soil between 1970 and 2014. So 9/11 accounts for 85% of all fatalities from terrorist attacks during that 44 year span. The Oklahoma City bombing accounts for 5%, and all other terrorist attacks - over a 44 year span! - account for 10%. There were 244 terrorist attacks with at least one fatality, and 2646 total attacks in that time. Less than 1% of terrorist attacks (9/11 and Oklahoma City) account for 90% of fatalities from terrorist attacks.
Basically the only reason people fear attacks by Islamic extremists or think they're extremely prevalent is due to the severity of 9/11.
Here's what I used: