Compute the average of values against the 5 most recent dates of each Category

Here is a simple 3 column dataset showing Categories, Date and Value

Catagorie	Date	Value
Fish	08-12-2015	6
Crab	05-12-2015	7
Crab	04-12-2015	6
Bird	27-11-2015	4
Snow	25-11-2015	10
Cat	21-11-2015	7
Dog	12-11-2015	5
Dog	28-10-2015	5
Fish	12-10-2015	3
Bird	11-10-2015	9
Dog	22-09-2015	9
Crab	17-08-2015	8
Cat	11-08-2015	1
Fish	20-07-2015	5
Crab	03-07-2015	2
Fish	02-06-2015	8
Fish	26-05-2015	9
Dog	14-05-2015	4
Snow	07-05-2015	7
Bird	03-05-2015	9
Cat	20-04-2015	10
Cat	15-04-2015	2
Snow	13-04-2015	3
Crab	29-03-2015	5
Crab	23-03-2015	2
Bird	14-03-2015	5
Cat	14-03-2015	1
Dog	26-02-2015	9
Fish	16-02-2015	4
Fish	08-02-2015	6
Bird	18-01-2015	1
Snow	06-01-2015	10

The objective is to compute category wise average of values against the 5 most recent dates.  So the expected result is:

Categorie	Category wise average values on 5 most recent dates
Bird	5.60
Cat	4.20
Crab	5.60
Dog	6.40
Fish	6.20
Snow	7.50

So for the Category of Fish (dates are sorted in descending order), the average should be 6.2 (average of 6,3,5,8,9)

Catagorie	Date	Value
Fish	08-12-2015	6
Fish	12-10-2015	3
Fish	20-07-2015	5
Fish	02-06-2015	8
Fish	26-05-2015	9
Fish	16-02-2015	4
Fish	08-02-2015	6

I have solved this problem using the PowerPivot. You may download my solution workbook from here.