[quote=@Rare]
Are most of the zombies in stage one?
[/quote]

I personally would think so, just by the fact that they are the ones that developed first. If the outbreak is fairly sudden, like it seems to be in this case, then I think what happened is that a vast majority of the infected have been bitten within the last week or so. However the local "Patient Zero", the one to bring it to the city, could feasibly be a level 3 or level 4. Either way, as time goes on we will be seeing more and more later levels. By the third week, we will be swimming in level 3's and 4's...