With all the supposed facts thrown around vis-à-vis school shootings, here are six statistics you should know related to the subject:

1. According to the Indicators of School Crime and Safety: 2015, between July 2012 and June 2013, there were 31 homicides of students aged 5-18 that occurred either at school or while traveling to or from school, which meant that an American student had a less than one in a million chance of such a thing happening to him or her.

2. According to a 2004 Secret Service report, titled the Safe Schools Initiative, that examined 37 incidents of “targeted school-based violence” between 1974 and 2000, 98% of the assailants experienced or perceived a major loss prior to the attack; 78% of them had a history of suicide attempts or suicidal thoughts prior to their attack, and 71% felt they had been persecuted, bullied, threatened, or assaulted by others.

3. A 2016 report from the National Center for Education Statistics found the percentage of students carrying a weapon onto school grounds in the last 30 days was 12% in 1993 and plunged to 4% in 2015.

4. According to the CDC, roughly 50% of those who commit homicide at a school give some type of warning signal, such as making a threat or leaving a note, prior to the event.

5. A 2010 study stated that 75% of students struggling with mental illness did not receive mental health services.

6. As the Iowa Department of Homeland Security and Emergency Management reported, culling from various studies, 27% of school attackers exhibited interest in violent movies; 37% of them showed interest in violence in their own writings, poems, essays, and journal entries.