I would think 30% is pretty much the absolute cap these days as to what can be acheived by an outstanding player in a regular (non-turbo) structure, one table at a time.
In practice, most SnG players have forgotten what it's like to play one at a time

(I'm completely serious), and therefore anything ~20% is considered excellent, but that takes into account some multi-tabling and a turbo structure.
With the number of games you've played, it doesn't tell you much other than it's obviously slightly more likely that you're a winning player than a losing one. As a rule(s) of thumb, I'd say:
- Nothing less than ~500 games at any level counts as a meaningful sample. This figure is not some random largish number thrown about for the sake of it - it's to do with the statistical probability that your results will be within a certain margin of error (caused by short-term 'luck') of where they should be.
- If you play 500 games and have a +ve ROI%, you're
probably a winner, although how much of a winner is undeterminable.
- If you play 500 games and have a double digit ROI%, or 1000 games with pretty much any +ve ROI%, you're almost certainly a winner.
- If you play 1000 games with a double figure ROI%, you're almost certainly a solid winner and a really good player.
- You need to play well into the thousands - like more than 3000 - of games to get an idea of what you're actual ROI% is. In practice of course this just doesn't happen - unless you're spacegravy - because people's play changes over this period, they improve, move up, whatever.
GL anyway
And fwiw my own sample is still < 2000 games total across several buy-ins and structures, so other than the fact that I am up overall, I'm pretty much statistically in the dark

"What's money? A man is a success if he gets up in the morning and goes to bed at night and in between does what he wants to do."
Bob Dylan