Data for print runs of comics, by issue?

[Jaws1965]

Is there a data source to learn how many issues of a certain comic, by issue, by variant, by printing, were originally printed?

 

For example, I've heard Walking Dead #1 (first printing) ran about 7,000 copies. I assume that general printing quantity continued for several issues before the title really took off, and printing massively increased.

 

I also read somewhere that the 1991 X-Men #1 was the largest print run of all time at around 8 million copies, and that nowadays, no comics even come close to that level. What about Spider-man 700? What about Revival #1 (first printing)?

 

So, how about Godzilla (1977 Marvel) #1 for example? Is this data available anywhere?

 

Does one have to be an industry insider to get this info? I'd appreciate any tips on this!

[DocGo]

This site sorta has some of the info you're looking for: http://www.comichron.com/

 

Don't know if the sales equal the amount printed but it's a good start.