Age of Marlin .22LR

Hey guys, I'm trying to work out the age of a couple of Marlin 795's. The only info I found said to subtract the first 2 numbers from the serial number from 100 to get the year of manufacture. It shows them as 1978 & 2011 I.E MM22***G = 1978 & MM89***H = 2011 Did they make them over such a long period of time ? They're almost identical so I have a hard time believing they're 33 years apart.

https://www.mcarbo.com/marlin-795-ma...nufacture.aspx

If you have a serial number starting MM, I think you are looking at 2010

Thanks ROKTOY I got 1 in 2011 so the counting back from 2100 works for that rifle but the MM after 2010 works too. Not the easiest info to find, thanks for the link.