You could add some more 9s to that, but it's a bit of a grey area because when you get down to a subatomic scale the idea of physical objects and their positions gets a bit unclear. If you think of it in terms of protons, neutrons and electrons as tiny objects, then the gaps in between are vast in comparison. The classical simplified models and diagrams are nonsense in that sense - if a proton is the size of a pea, the electrons should be tens of metres away, not a centimetre or two. But the classical simplified diagrams are so simplified that they're just basically wrong. It's not like moons orbiting a planet (or planets orbiting a star), as those models imply.
No walking through walls for us