Finish Distributions

[Taraz]

How many SNGs do I need to play before I can get a reliable finish distribution? I've been getting a few more 2nd place finishes than 1st and 3rd place finishes although I don't think I'm playing too tightly when I get ITM. Also I'm slightly worried that I'm finishing in 5th twice and often as I am finishing in 4th. Should I worry if I've only played 286 at the 22s and 33s and my finish distribution is the following?

Total Tourneys played: 286
ITM: 39.16%
ROI: 19.71%

1st - 35 - 12.24%
2nd - 46 - 16.08%
3rd - 31 - 10.84%
4th - 20 - 6.99%
5th - 39 - 13.64%
6th - 31 - 10.84%
7th - 34 - 11.89%
8th - 23 - 8.04%
9th - 11 - 3.85%
10th - 16 - 5.59%