Simply sum percentage, it seams good (33.88%) . But net income (Total gain&lose) is not good as it should be (cost * %gain&loss=11740.01) considering cost I spent. Is there any hand on experience can help to optimize the net return?
You can sum absolute values, but not percentages. Percentage growth/decline can be summed in Log-space, or you can multiply the factors (the number before you subtract 1). Ie. you can subtract 100% many times, but won't have any real effect after you've first multiplied with zero (0). Basics very important to get to where you want to be in trading. Not just 1 + 1 = 2, but also what + and = means, and what every step of the way really means. In order to optimize your trades, you need to look at them in aggregate and learn from them to that point where you get ideas for optimizations.
Like @Simples says, you can't just add it all up. Also, your % don't add up, 972 profit on 2642 inv = 36.8%... the rest don't seem correct either. You could look at return on average investment... because I assume these are 10 different trades right? So, 981 profit on 3.465,- average investment... but it looks very skewed and that doesn't help your analysis. How to optimize it? What did you do on your 2nd trade? Do that (unless it was a fluke/luck/no-idea-what-happened-but-I'm-in-the-plus). And look at your 4th and 6th trades... don't do that... Basically, assess and analyse and assess.... and analyse