Ok, I'm not digging down into the contextual relevancy of what should/shouldn't be considered a "school shooting" but since the criteria is supposedly the same the numbers should be at least somewhat relevant among each other.
School shootings in the United States - Wikipedia
The WORST decade in the last century (1990's) saw 62 shootings. With the better part of 2 years still on the clock in this decade that list shows 148.
Now realize that gun paranoia is so rampant in schools now that you can have a kid suspended for chewing his pop-tart into a gun shape and yet...
I can remember when it wasn't just normal but ubiquitous for boys to have pocket knives in school, often openly worn on the belt. Kids in the South/Mid West would bring guns to school for hunting after classes. Even if there IS something to discuss regarding guns it's a long way downstream from what in the hell is going on with people willing to simply kill for no fathomable* reason. The simple truth is people's willingness to commit these kinds of atrocities is outstripping anything as myopically simple as the inanimate objects used. Until we can get some useful grasp on what's actually driving the acts themselves most gun control is just trying to cut heads off the Hydra.
*Wanting to kill people isn't new and often you can at least "understand", on some level, why the spouse offs the cheating partner or the guy kills the person stealing money from them or what have you. (let's not confuse understanding with condoning) This unhinged "people are gonna die" thing is just different.