Islamist Terrorism in the US

Q19: Will there be a lethal Islamist terrorist attack in the US in 2015?
Yes: 35%
No: 65%
(see definition note for question 18)

 The terrorist attacks in October, together with the more recent attacks in France and Australia, have increased the perceived risk of a Islamist terrorist attack.  Since 2000, there have been lethal Islamist attacks in the US in 2001, 2002 (2 incidents), 2006 (1 debatable incident), 2009 (2 incidents), and 2013 (1 incident).  This suggests a 33% estimate (with a 5-year half-life of decay).  The recent attacks outside the US are not counted in this estimate, so I will increase it to 35%.