Domain's Age Completely Blank

[denny7640]

Hey everyone,
I recently added my domain for Sale on Godaddy.
But when I type in my domain...it does not show its age. Under the "Age" box, its completely blank.
Whereas other people's domains do show the domain's age under the "Age" box.
Why is that so?
How can I show my domain's age on my Godaddy sale listing?

how to get a birth certificate?

Pls help.