Well, I remembered reading about this in the general guidelines before I started keying that said ...

"Years

Years should be entered as 4-digit years when possible. If the year on the image is only 2 digits please try to determine what century the event occurred in. There is typically information on the image that will assist you in determining if it is 2008 vs 1008. If you are unable to determine the century please key the two digit year."