Dang it, that's a hard variance to calculate. I'll just tell you how to calculate this percentage, and you can try to calculate your variance on your own.
(1) Take the number of units above basic strategy EV. So, in the case where I was looking at breaking even, that would be 0 - (-115) = 115 units above expectation.
(2) Estimate your standard deviation by multiplying the standard deviation per hand (probably between 2 and 3) by the square root of hands played. So, in the case where I estimated your SD/hand at 3, your SD was 3*sqrt(230*100) = 455 units.
(3) The answer from (1) divided by the answer from (2) is your z score - it's a mathematical expression of how far you are from the mean, measured in SD's. So in the previous example, z = 115/455 = 0.253.
(4) You can convert z to a probability using free calculators on the Web (it's a mathematical function, so there's an exact formula if you want too). I used the first one that came up by Googling "z score calculator" -
http://www.fourmilab.ch/rpkp/experiments/analysis/zCalc.html. z = 0.253 corresponds to probability (Q) = 0.400, or 40%.
You can do these steps with your actual winnings and actual SD once you figure out your actual SD. It's not trivial, but straightforward. If you look at Prince Dragon's attachment, the SD (Std Dev) is listed just to the right of the Results (EV). Remember to normalize everything to units or dollars, but don't mix both.