Question about rear main seal on jetta.
 

I own a 1990 volkswagon jetta carat.I found out that I was haveing oil comeing out of my rear main seal.Goodyear put a dye in the oil to see where the leaking oil was comeing from and found out some was comeing out of the rear main seal.My question is that should i get the seal fixed or is it normal to have a little bit of oil leaking from the rear main seal on older cars like my jetta.Any input on this would help.