Calculating Totals

I am attempting to build a spreadsheet for work, and I'm having trouble calculating a correct total.

In essence, the bit of my spreadsheet I'm concentrating on is 2 columns:

Column A is headed "Type of Work" and Column B is headed "Completed".

The Type of Work will either be Letters or Memos, and the Completed will either be Yes or left blank to indicate No. For other reasons, No has to be represented by a blank cell.

At the moment, I have 12 rows, going from A2 to B13, with data such as the following:

Letters Yes
Letters Yes
Letters
Letters
Letters Yes
Letters
Letters Yes
Memos
Memos Yes
Memos
Memos
Memos Yes

I need a summary section at the side with the following calculations:

Total Number of Entries
Total Number Outstanding
Total Number of Letters Outstanding
Total Number of Memos Outstanding

However, as I have only populated it with 12 rows of data for my testing purposes, I need to build formulas to take into account the fact that a maximum of 2000 rows may be filled in by other people over the next few months. Therefore, my formulas look like the following:

Total Number of Entries (stored in E2):
=COUNTA(B3:B2000)

Total Number Outstanding (stored in F2):
=E2-(COUNTIF(C3:C2000,"Yes"))

Both of the above formulas work perfectly, and when I enter a 13th and 14th row, the totals update as I want them to, so I have no problems there.

However, I am struggling to enter a correct formula which will calculate the total number of Letters that aren't Completed.

I did set some names and tried to use:
{=SUM((Type="Letters")*(Completed="Yes"))}

but it gave me a #NA error, presumably because the named range was looking at all the empty cells up to A2000.