A recent study indicates that 31% of gun owners have used a gun defensively at least once over their lives. (I am in this category, and many of my students have confirmed their own defensive gun use (DGU) experiences.)
Furthermore, the same study indicates 82% of these defensive gun uses do not require firing of the gun. In other words, merely dispalying the gun in some manner was effective in stopping the attack. This is consistent with previous studies done by John Lott and others.
Year to year, it may not be a huge risk. But over a lifetime, your risk of being subjected to violent attack is roughly of the same magnitude as your risk of being in a serious car accident (about once in a lifetime).
This should be sobering enough to get you into the free handgun training I offer here.