"The National Counterterrorism Center (NCTC) was created in 2004 to ensure, in part, that U.S. government agencies have appropriate access to and receive the intelligence necessary to accomplish their assigned missions. NCTC is the U.S. government's central and shared knowledge bank on international terrorism and, in this capacity, NCTC provides the Department of State with statistical information to assist it in completing the annual 'Country Reports on Terrorism' (CRT). NCTC also uses this information to compile its own annual 'NCTC Report on Terrorism' (NRT). Title 22, Section 2656f of the United States Code (U.S.C.) requires the Department of State to include in its annual report, 'to the extent practicable, complete statistical information on the number of individuals, including United States citizens and dual nationals, killed, injured, or kidnapped by each terrorist group during the preceding calendar year.' […] The statistical material in this unclassified report is drawn from terrorism incidents that occurred in 2011, as reported in open source information. This open source material is the most comprehensive resource that NCTC can use to compile and provide the statistical data necessary to the Department of State to fulfill its legislative reporting requirements"
National Counterterrorism Center: http://www.nctc.gov/