The US is averaging more than one mass shooting per day in 2015

Before the shooting in Roseburg, Oregon, on Thursday that left 10 people dead, the US had gone nearly 48 hours without a mass shooting.

And that's abnormal, according to the Mass Shooting Tracker.

The tracker was created by the moderators of the pro-gun control subreddit Guns Are Cool. It tracks every instance in the US in which a gun is used to kill or injure four or more people at one time.

As of October 2, there have been 294 mass shootings in 275 days in 2015. Those shootings have claimed the lives of 380 people. No more than eight days this year have passed without a mass shooting.

The tracker's definition of a mass shooting differs slightly from the official FBI definition, which says that an event qualifies as a mass shooting if four or more people are killed.

"The most obscene incidents of gun violence usually do not make the mainstream news at all," Guns Are Cool reasons on the Reddit page for the Mass Shooting Tracker. "Why? Because their definition is incorrect. The mainstream news meaning of 'mass shooting' should more accurately be described as 'mass murder.'"

Based on these numbers, President Barack Obama's claim that these kind of events have become "routine" rings true.

"The reporting is routine, my response here at this podium is routine, the conversation in the aftermath of it - we've become numb to this," a visibly frustrated Obama said Thursday at the White House in the hours after the Oregon shooting.

He added: "I hope and pray that I don't have to come out again during my tenure as president to offer my condolences to families in these circumstances. But based on my experiences as president, I can't guarantee that, and that is a terrible thing."