Thank you for replying!
I don't think I understand the maths. BTW, I'm not trying to download more torrents than I can. I just asked because I found it odd, that the highlighted line does not move, the more I seed.
I think it should 
Think gamification. It's good to achieve something, just by seeding.
My ratio is currently 0.501, but in the Rationator table the 0.3 row is highlighted. I assume it is because I have downloaded less than 10 GB. Thus my download limit is 2 torrents a day.
Linking the privileges to the downloaded amount, rather than the ratio, is kinda defying the purpose of the ratio-system, isn't it? Shouldn't it be linked to the uploaded amount and/or the ratio?