(CNN) - After Tuesday's shooting at an Oregon high school, many media outlets, including CNN, reported that there have been 74 school shootings in the past 18 months.
That's the time period since the December 2012 massacre at Sandy Hook Elementary School in Newtown, Connecticut, where 20 children and six adults were shot to death.
Without a doubt, that number is startling.
So on Wednesday, CNN took a closer look at the list, delving into the circumstances of each incident Everytown included.
Everytown says on its web site that it gleans its information from media reports and that its list includes school shootings involving a firearm discharged inside or on school grounds, including assaults, homicides, suicides and accidental shootings.
CNN determined that 15 of the incidents Everytown included were situations similar to the violence in Oregon - a minor or adult actively shooting inside or near a school. That works out to about one shooting every five weeks.