Define a calculation field for each of your 4 options. I'll pretend that the literal values selected are "A", "B", "C" and "D". Substitute the actual values in these calculations:
DropDownField = "A"
DropDownField = "B"
and so forth...
Define summary fields that compute the total of cOptionAFlag, cOptionBFlag, and so forth....
Sort your records by Month. You may need to define a calcualtion field to produce the correct value for this sorting such as:
DateField - Day (DateField ) + 1 -- which returns the date for the first day of the month for all dates of the same month.
With the summarized records data source option, Your various Y-series data can refer to the four summary fields that selectively compute these counts.
PS. If you are fairly conversant in SQL, the ExecuteSQL function might be used to produce the same values without the need to add so many new fields to your table.
I had a feeling it would come to that. Unfortunately, I have another 8 or so fields each with 5-10 options I would like to search by, resulting in over 100 extra fields. So, I think I better brush up on my SQL. Thank you for your response.