Yes, I can see that in the terms of probability you will eventually lose money, but I still don't know why it seems that I keep winning money.
The reason is, you are lucky lol.

Is there any global statistics like know much profit/losses?
You may check the Statistics tab.
For example, people have "won" 218.547 btc in green x0.4, meaning the total waged amount for those bets are 218.547/0.4 = 546.3675.
Similarly, you can work out green x1.0, green x1.1, etc, and calculate the total waged amount and total won amount
