In the recent RadioLab podcast "Quicksand," a reporter was able to give exact metrics on the popularity of quicksand by looking at the number of quicksand mentions in movies from 1909 until the present. In the course of his research, he was able to show that 1 in 1000 movies from the early part of the century used quicksand, but that by the 1960s, that had changed to a massive 1 in 35. Culturally, quicksand spoke to the metaphors of Vietnam, Civil Rights, and other fears associated with that decade.
The current fad, of course, is the "Zombie Apocalypse." I love The Walking Dead, 28 Days Later, World War Z (the book at least), and the like. And, clearly there is something about this fad that has tapped into the current Zeitgeist.
In order to understand that, however, I need data. Is there a study that can serve as a decent proxy to attest to the actual prevalence of zombies in popular culture over time? My gut tells me there would be a spike sometime in the recent past - I don't remember zombies being "big" in the 80s, beyond Night of the Living Dead - but nowadays, even Jonathan Coulton is getting in on the act.
What numbers would help me to quantify the actual prevalance of zombies in popular culture, in order to demarcate the inflection point of this phenomenon?
Clearly, every age has its monsters (vampires, werewolves, killer plagues) and so I don't mind a relative comparison. For bonus points, are there studies that attempt to isolate what about zombies so matches what the culture is trying to tell us?