report program to calculate attrition rate or employee?

Hi all,

I have to prepare a report program to calculate the attrition rate.

I am done with most of the work, but i am confused about something.

I have made 4 parameters , and a date range.

So accordingly i am having my select queries.

But attrition rate requires, total employees before the daterange-low,

and newly joined, and left employees.

the queries will get the data only between the dates.

So how to get the total no. of employees before the starting date and the no. of left employees??

Any help would be apperciated.

Regards

Tarun