According to the IAEA Illicit Trafficking Database (ITDB), between 1993 and 2007 there was 1,340 confirmed incidents of nuclear and radioactive material trafficking in the world.
The breakdown of the incidents as reported by the ITDB fact sheet:
Of the 1340 confirmed incidents, 303 incidents involved unauthorized possession and related criminal
activity, 390 incidents involved theft or loss of nuclear or other radioactive materials, and 570 incidents
involved other unauthorized activities. For the remaining 77 incidents, the reported information was not
sufficient to determine the category of incident.