The Shape of Code

If 10 people independently implement the same specification in the same language, how much variation will there be in the length of their programs (measured in lines of code)?

The data I have suggests that the standard deviation of program length is one quarter of the mean length, e.g., 10k mean length, 2.5k standard deviation.

The plot below (code+data) shows six points from the samples I have. The point in the bottom left is based on 6,300 C programs from a programming contest question requiring solutions to the 3n+1 problem and one of the points on the right comes from five Pascal compilers for the same processor.

Multiple implementations of the same specification, in the same language, are very rare. If you know of any, please let me know.