[Hobbes]

can't tell you exactly, but as the Contemporary changed the numbering system zu CCX3-xyxy somewhat in 1983, yours should be approximately from 1981.

On the left side behind the front wheel on the round 4" tube should be the stamp of the number of the frame. With this number you can read out the date of build of the frame. You will find the exact reading in the Contemporary section in this forum.
Good luck