Scatter Chart - Calculate total % contribution for top 10 dates/customers

[#1]

I am trying to build a scatter chart that will show me the relation between 'total % of sales for top 10 dates' and 'total % of sales for top 10 customers'. My example data is as below:

SalesDate	Product	Customer	Sales
15/01/2015	A	1	50000
23/02/2015	A	2	25000
30/02/2015	B	3	5000
05/03/2015	C	3	100000
12/03/2015	B	1	20000
30/03/2015	D	5	453246
04/04/2015	C	1	576556
07/05/2015	D	3	242364

What I need to calculate is as follows:
total % of sales for top 10 dates - calculate %contribution of sales done on top 10 sales date to the overall sales for a given product

total % of sales for top 10 customers - calculate % contribution of sales done with top 10 customers to the overall sales for a given product.

For this I believe my scatter chart dimension must be Product?

I am having difficulties calculating my X and Y field. I am currently using below expressions for X and Y field:

X : sum(aggr(if(rank(aggr(sum(Sales),SalesDate)/sum(TOTAL Sales))<=10,aggr(sum(Sales),SalesDate)/sum(TOTAL Sales)),SalesDate))

Y: sum(aggr(if(rank(aggr(sum(Sales),Customer)/sum(TOTAL Sales))<=10,aggr(sum(Sales),Customer)/sum(TOTAL Sales)),Customer))

However, this doesn't work for me. Moreover, I have the Sales date across years and would like to see the above % contribution for a given year (to the overall sales for the same year). Please advise.

Thanks.

[#2]

Any suggestions on this?  I am still unable to figure out the X and Y fields.

Thanks,

Ami