Well, just in time for Halloween, we get this:

If you like this graph, you should most certainly read the whole story "
War and Social Upheaval Cause Spikes in Zombie Movie Production." My inner number geek picked up on some issues with the sampling that went into this: frankly, to objectively demonstrate this, what is needed is a chart showing the relative importance of zombie flicks per total movies produced in any given year.
What's that you say? Oh right, this is an archaeology/anthropology blog. Uh, ok, well.
Here you go! Did you know that the earliest documented zombie outbreak is at the important MSA site of Katanda (Brooks 2003; McBrearty and Brooks 2000; Yellen et al. 1995)? And that, just last year, excavations at
Hierakonpolis, Egypt, revealed the first unambiguous evidence for a zombie outbreak in urban settings? Happy Halloween, folks!
References
Brooks, M. 2003.
The Zombie Survival Guide: Complete Protection from the Living Dead. Three Rivers Press, New York.
McBrearty, S., and A. S. Brooks. 2000. The revolution that wasn’t: a new interpretation of the origin of modern human behavior.
Journal of Human Evolution 39:453–563.
Yellen, JE, AS Brooks, E Cornelissen, MJ Mehlman, and K Stewart. 1995. A Middle Stone Age worked bone industry from Katanda, Upper Semliki Valley, Zaire.
Science 268:553-556.