"Unit Weight" of DB strings

[Thomas Erickson]

I'm wondering if anyone knows of a reference for the unit weight of bass strings - that is, the actual mass of a string for a given length.

With all the talk of "tension" that is bounced around in discussing different strings, as well as things like string-lengths and other instrument dimensions/modifications, I think it would be nice to know just how some various strings compare in terms of actual tension and not just "feel".