Converting PCGS/NGC serial numbers to dates

[Recyclersteve]

I have a friend who has asked me to help with a project. At first I thought it would be a piece of cake, but it is a bit more involved than I thought.

Essentially, he wants to be able to look at the serial number of a coin and determine an approximate date (or even year) when it was slabbed. I know about topics like old green holders and rattlers. But he wants to get a list of more specific numbers with corresponding dates of certification. Example of what we are looking for:

Coins with serial numbers from 6037485 to 8943615 were encapsulated in 1994. I'm just making those numbers up, but I think that may clarify what I am looking for.

If someone wants to ask me for specific numbers, try these: 4404841, 14549016, 15656626, and 26095465 (all PCGS) and 430011-008 (NGC).

We are trying to get this for both PCGS and NGC holders, but will settle for PCGS as we are looking at more coins in those types of holders. If anyone has a link to this information, that would be fantastic. And, no, I am not a PCGS or NGC member with access to certain tools that may not be available to the general public.

Thanks in advance.