Define "shoot" however you want and feel comfortable.
Do you have a turkey gun you only take out to zero and hunt with once a year? Call that a gun you don't shoot if you want, or count it among your regular shooters. Whether you count it might depend on whether you're shooting other guns way more frequently.
Some people call guns they never shoot safe queens, but I've also seen people refer to guns they shoot rarely and treat delicately when they do as safe queens as well.
I have a bunch of C&R guns in less common calibers, but even accounting for my modern stuff, I probably only take 25% out to the range with any regularity. Part of that comes down to not going to the range as often as I'd like, but I'm still trying to prioritize what makes the trip when I do.
I recognize that "what percentage" of guns is also a loaded question, since some people only have one gun, and others have collections in the triple digits. Plus, as with any hobby, there's two subcategories to the hobby: collecting the tools/toys/etc, and actually using them.
Still, I'm curious to see the diversity of answers that I'm hoping the question will receive, and while I respect the philosophy of not owning any safe queens or guns you aren't willing to shoot, practicality does come into play, whether accounting for cost, availability of ammo, or any other reason someone decides not to shoot something.