How are the hours counted?

So with the new update now arriving to League, I was curious to see what veteran reward I'd get, (http://www.surrenderat20.net/2017/09/preseason-update-forge-your-path.html#2) considering how I have put in a significant amount of hours into this game, spanning from 2011. (and some breaks here and there, one year break between 2014-2015) But when I checked, I'm receiving the "Defender of the League" Which is at least 500 hours up to 1499 hours. So I'm wondering, how does League count my hours? Because I'm 100% certain that I would at least have the Champion of the League, unless my transfer from EUNE to EUW reset my hours?