Perform an aggregation on Top x items after satisfying certain conditions

Visualise a 5 column dataset as show below.  This is a very small sample of the actual dataset.  It shows the date on which supplies were received for each item from Vendors and whether those supplies had errors in them.  Finally those identified errors have been bucketed into relevant categories.  The Item ID# is a code assigned by the Client Organisation.  The format of the ID# is X [Last two digits of year of receipt] [Four digit Number].  For items received from a certain vendor, the last four digits of any item will always be in ascending order of the Date received.  In other words. for items received from a certain vendor, the last 4 digits of an item received on 13 January 2017 will always be greater than the last 4 digits of an item received on 11 January 2017 from the same vendor.  There will never be repetitions in the Item ID# column.

Vendor Name	Item ID#	Date Received	Error with Item?	Error Category
California	X170016	1-16-2017	No
California	X170014	1-13-2017	Yes	Labeling Error
California	X170015	1-13-2017	Yes	Packaging Error
California	X170008	1-9-2017	Yes	Quality Issue
California	X170003	1-2-2017	No
California	X160645	12-26-2016	Yes	Packaging Error
California	X160646	12-26-2016	No
California	X160644	12-25-2016	Yes	Labeling Error
California	X160638	12-20-2016	Yes	Quality Issue
California	X160633	12-15-2016	No
California	X160626	12-8-2016	No
California	X160625	12-7-2016	Yes	Packaging Error
California	X160624	12-5-2016	Yes	Labeling Error
California	X160618	11-23-2016	Yes	Quality Issue
California	X160613	11-13-2016	No
California	X160606	10-30-2016	No

The objective is to compute the error rate by vendor and Error category for the 10 most recent transaction dates with that specific vendor.  So, for vendor Name “California” and  Error category as “Packing Error”, this ratio should be computed as = Number of packing Errors on 10 most recent dates/10.

Here is a simple snapshot of the Data for California.  I have filtered the dataset where Vendor Name is California and then sorted the Date received column in descending order.  Please note that when i filter the dataset on California, a lot more rows are returned.  I am only showing the Top 10 rows here because that is what is important for solving this question.

Vendor Name	Item ID#	Date Received	Error with Item?	Error Category
California	X170016	1-16-2017	No
California	X170014	1-13-2017	Yes	Labeling Error
California	X170015	1-13-2017	Yes	Packaging Error
California	X170008	1-9-2017	Yes	Quality Issue
California	X170003	1-2-2017	No
California	X160645	12-26-2016	Yes	Packaging Error
California	X160646	12-26-2016	No
California	X160644	12-25-2016	Yes	Labeling Error
California	X160638	12-20-2016	Yes	Quality Issue
California	X160633	12-15-2016	No

The expected result is:

Row Labels	Labeling Error	Packaging Error	Quality Issue	Factory Error
Boise		30.00%
California	20.00%	20.00%	20.00%
Detroit	70.00%			30.00%
Ekalaka	20.00%			20.00%

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