You can't unless sn data has been published in a book.
Sorry I can't help more but all I can tell you is that it was made after 1940. The last serial number for 1940 was 398,400. At a guess, I'd say your rifle was probably made in the mid-1950's or perhaps later.
It took Savage 41 years to make the first 398,000 Model 99's, and production was interrupted during WWII. Civilian production didn't really get back into its swing until 1947 or 1948. Hence my guesstimate of not earlier than the mid-1950's.
I do not know the total production numbers for the Model 99 so it might have been made very much later than the 1950's perhaps even into the 1980's or 1990's. Sorry I could not be more help.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.