The ESP Guitar Company

I posted this here because my ESPs are signature. I completed a search on the site and Google and got some help but not the answer I was looking for. So the serial number on my Cavalera Sig is SS07064XX I understand the SS is signature series and I've come to the conclusion that 07 is the year. What I'd like to know: the 064XX Is it the production number of the guitar in the model name meaning it's the 64XX Cavalera AX built? Is there any way to know for sure where my AX falls in the production line?