DBCC show_statistics: density doesn't match what I calculate
The documentation for DBCC SHOW_STATISTICS says that Density (in the header) is:


  Calculated as 1 / distinct values for all values in the first key column of the statistics object, excluding the histogram boundary values.


It also says:


  This Density value is not used by the query optimizer and is displayed for backward compatibility with versions before SQL Server 2008.


You are using SQL Server 2005, so this value may be relevant to you in some circumstances, but I don't know exactly when 2005 would use that Density value.