SNG advice needed

Hi guys.

I decided to build-up a bankroll at FullTilt playing only 6-player SNG's. (Two players paid)

I started with $5 SNG's. So far my performance is as follows:

# of tournies played: 231
Finished first: 46 (20%)
Finished second: 64 (28%)
Finished 3rd, 4th, 5th, 6th: 121 (52%)

I finish in the $ 48% of the time and my ROI% is about 22%

What kind of performance do you think I should have before moving up to higher stakes SNG's?

Cheers

231 Tourneys played is not that big of a sample

the most important factor for me is your Bankroll Managment
even if youre really good at the Sng
id recommend a roll of at least 50 times the Sng buyin 100 to be on the safe side
then youre really comfortable and a downwing which will come doesnt pose a threat
and is less likely to put you on tilt or making you change your style out of fear

for the skill part i think that the 5 and 10 Sng arent that far apart (no personal experience) i have some with the 16 and 27 Tsngs at stars