Are you more likely to get trolls/AFKers in series?

I don't browse the forums much, so I have no idea if this is a new topic or not.

I've noticed that, when I get into series, there seems to be a disproportionately large number of trolls/AFKers, but I'm not sure if this is actually happening or this is just selection bias. I've kept track of this over some of my latest series, and I've found that:

In 40 series games, 11 had a troll/AFK on my team. I define "troll/AFK" as someone who went AFK (obviously) or somebody who was clearly and intentionally trying to lose - I don't count "troll picks" or off-meta (e.g. you want Ziggs adc? fine with me) in this count, unless there was a particularly good reason to do so (one example from this count: "xxxxx: fucking instalok enjoy duo top).

In 40 non-series games, only 3 had a troll/AFK, by the same definition as before.

Interestingly, though I haven't kept stats on this, there seems to be the same disproportionate chance at a troll on the other team when they have a member in series. Last game the other team had a Thresh ADC who trolled for most of the game, so I looked up the other team: indeed, their Shaco was in series..

Have other people experienced the same, or am I just imagining this?