How often do you win?

Sorry if this has been asked before. But I've looked around on profiles and reviews of SteamGifts and it basically shows that people often win every 130-200'th entry. But I have seen some people with like 500-600 and only 1 win.
So please, tell me how often you win / after how many entries you win and tell me it here so I can kind of get the average of entries before you win.
I know that the system randomly chooses someone from the entry list and shieet, but still.