So what does it for reports for toxicity to take effect?

So after a game, me and my whole team agrred to report this Darius. Never joined team fights, made a anti-American comment after the fight, complained how the support was 0/3/8 (which was me), so nothing too different other then everyone ageing to report him.

But because he was so confident that our reports would do nothing, it got me wondering. Just how much does it take for a report to get noticed?