From the Executive Summary: "The '2018 Arson Incident Report (AIR)' is an informational product prepared by the United States Bomb Data Center (USBDC), using incident data reported in the Bomb Arson Tracking System (BATS) by its nearly 2,764 interagency partners and 13,059 registered users. This report examines the total number of fire-related incidents reported in BATS for calendar year 2018 and includes 'Incendiary (Arson), Undetermined, Accidental' and 'Natural' fire-related incidents. [...] From January 1, 2018, through December 31, 2018, BATS captured a total of 22,723 fire-related incidents. Of these, there were 6,532 incidents reported as 'Incendiary or Arson,' which accounted for 29 percent of all the fires reported. The total amount of damages for all fire types was estimated at more than $882 million, with 1,225 injuries and 643 fatalities associated with the 22,723 reported fires. 'Available Combustibles' was identified as the most widely utilized incendiary fire subtype, while 'Residential' was identified as the most targeted property type."
Bureau of Alcohol, Tobacco, Firearms and Explosives: https://www.atf.gov/