I hope someone can help me with this Excel problem, otherwise I'll need to buy another 3rd part control to handle the Pivot problem we've encountered. I know it's somewhat off-topic, but hopefully someone can/will help.

We have raw data that includes the following type of data:

```
ID Date Type
1 11.05.2009 0
2 12.05.2009 0
3 13.05.2009 1
4 14.05.2009 0
5 15.05.2009 0
```

As you can see, those five rows are from the same week.

We've organized the pivot data so that it groups by week, and we'd like to configure either a formula, calculated field, or whatnot to calculate that 1 out of 5 rows has a 1.

In other words, since there is 1 1'er, and 5 in total, we'd like to have a field that says "20%".

However, we can't figure out how to trick Excel to count the number of rows that went into a pivot cell, and sum the same rows, and thus calculate SUM/COUNT.

It seems our calculated field is done pr. row, and thus useless to us.

Basically, we'd like this:

```
Percentage
Week
19 0%
20 20% <-- this is the week from the data above
21 0%
```

Adding a calculated field that has this formula:

```
SUM(Type)/COUNT(Type)
```

does not produce the right data, we're just getting a 0 or 1 pr. row, basically it looks like Excel does this:

```
ID Date Type (Calc)
1 11.05.2009 0 0 (0/1)
2 12.05.2009 0 0 (0/1)
3 13.05.2009 1 1 (1/1)
4 14.05.2009 0 0 (0/1)
5 15.05.2009 0 0 (0/1)
```

Does anyone understand my problem? Does anyone have any hints?

It seems DevExpress Pivot control handles this, but we'd like to avoid this for the time being, if possible.