ths, extremist sympathizers and mobilized supporters, by ideological category 454.1 Affiliation of those committing terrorist offences 584.2 Terrorist incidents and killings per 1,000 members of extremist organizations 604.3 Major terrorist groups in America, 1955-2000 614.4 Distribution of terrorist attacks, by target and group ideology 624.5 Number of victims killed in different types of attack,