No, we're not talking about how many characters George R.R. Martin has killed off, but how many readers of his multivolume series A Song of Ice and Fire. He published the first volume, A Game of Thrones, in 1996. It was a huge publishing success. Many people read it. Not all of those readers are still alive.
Jerzy Wieczorek, a doctoral student in statistics at Carnegie Mellon University, speculates that about 40,000 readers who began the series did not live to see the publication of the fifth novel, A Dance with Dragons. We can reasonably conclude that George R.R. Martin is responsible for their deaths, most of which were gruesome and cruel.
-via Flowing Data