Nobody can really say for certain. The only way to *really* know would be to measure your paint thickness before/after the work and then extrapolate from the differnce. But most correction by PCDA is so mild that you wouldn't even get a difference in the two readings.
Every time you polish out marring you take off a little more clear. The rule-of-thumb is that you can only take off about one third of a mil (that's .0003") without precipitating clearcoat failure. That isn't much, but the PC/DA doesn't take much off either.
Short answer, and this is just *IMO* and a wild guess based on experience: you can do that once a year for a long time. You can do it more often than that for a less-long time. You shouldn't *have* to do it more than once a year, if you do you oughta rethink/change your wash/etc. technique. FWIW, I do that sort of correction on my MPV (thin factory clear, sorta fragile) about every other year and I don't try to remove the deeper scratches.
If you're gonna keep the vehicle for a long time, and you find that you keep marring it (that's not intended as a slam, most people do it even when they're skilled and careful), you might oughta consider living with some imperfections in the interest of your paint's long term well being. I sure wish I'd done less polishing on my '85 Jag...by the time I figured out how to wash it properly I'd polished the paint nearly to death and now I can't do more correction so I have to live with marring that bugs me
