Code Churn

Just a mental note.

When discussing programmer productivity kloc (kilo-lines-of-code) per year is often used as a general purpose metric. I presume this is based on measuring the size of the code-base and dividing by the time taken to write it. For example i have written ~5k in 10 months so I write aprox 6 kloc per year. This measuremnt hides the fact that that 5k of code has been rewritten many times, so I have probably written much more that 5kloc. Measuring how many lines of code were altered at each subversion commit and summing them up over the year would give a better idea of how much code I have actually written. I call this figure code turnover (analagous to (european) business turnover).
The ratio of turnover to the size of the code at the end (code profit?), I'll call the code churn ratio, or just churn. I wonder what kind of numbers are typical for churn? I guesstimate my churn on this project to be at least 2 and it wouldn't surprise me if it was higher.

PS. If you are wondering why I haven't posted in a while, it's because I am stealthily working on my new site