Conditional selection of group to total/count

[suemon]

I am writing a report that summarizes total number of customer visits per year then averaging the number of visits per month. This is all simple but I need to change the 'averaging' for the current year to divide by number of months passed rather than the simple /12.
Making the divide by a dynamic figure to give me a month average is fine. My problem is being able to total those dates starting only with 2008. Can anyone help?

 

[lbass]

You should probably be in forum149 or forum767. Anyway, you can use a denominator like this, assuming you would evaluate through the last full month:

datediff("m",date(year(currentdate),1,1),maximum(lastfullmonth))+1

To conditionally total those records within the current calendar year, you could use a formula like this:

//{@incurrentyear}:
if {table.date} in date(year(currentdate),1,1) to maximum(lastfullmonth) then
{table.visit}

Then you can use:

sum({@incurrentyear})/(datediff("m",date(year(currentdate),1,1),maximum(lastfullmonth))+1)

-LB