To put that in a personal context for myself, the first novel, A Game of Thrones, published just before I began my freshman year of high school. The most recent volume, A Feast for Crows, came out in 2005. That was the first year I attended Carnage. The book hit the week before the convention.
In fact, I saw Feast for Crows at Carnage. We were playing a GURPS Banestorm adventure when Chuck strolled up and handed one of the players a copy. She squeed a bit. I think that was the first time I encountered the series at all.