Finding the Employees Churn rate

[nxmogil]

Hi Friends, 

I am working on a project where I need to find out employee churn rate for 2001

that means employees left in 2001 /total employees depratement wise. 

please help me with ideas

This is the sample data 

input emp_no dept_no $ dept_name $9.from_date to_date ;

 10058 d001 Marketing 25-04-1988 01-01-2023
10108 d001 Marketing 06-12-1999 20-10-2001
10694 d001 Marketing 26-01-1988 11-07-2001
10787 d001 Marketing 19-07-1991 27-07-2002
10906 d002 Finance 18-10-1998 25-04-2001
12547 d002 Finance 17-10-1997 19-03-2002
12564 d002 Finance 03-11-1998 01-01-2023