Relative % in Pivot Table

[#1]

I just want to create an expression that will provide be a % of the total count of presentations given per the week dimension. 

I am counting the number of Presentations that are certaion plan types in a given week. 

Below is the formula I am using and I am having problems. 

count

({$<PlanDescription = {'*Life*','*Senior*'}-{'*Paid Up*','*Select*'}>} Distinct PresentationID)/

count({$<PlanDescription = {'*Life*','*Senior*'}-{'*Paid Up*','*Select*'}>} Distinct total <Week> PresentationID) 

I attached an excel verion of my pivot table in QV...my percentages appear to be off...

Any suggestions would be greatly appreciated.  Thankd in Advance!

Week	Coverage Amount	Pres Cnt	% of Pres
01/17/2013	15k	8	33%
01/17/2013	<15k	9	38%
01/17/2013	>30k	2	8%
01/17/2013	30k	3	13%
01/17/2013	20k	2	8%
01/17/2013	>15.01K<20k	1	4%
01/17/2013	>20.01K<30k	2	8%
01/10/2013	15k	8	29%
01/10/2013	<15k	11	39%
01/10/2013	>30k	1	4%
01/10/2013	30k	4	14%
01/10/2013	>15.01K<20k	2	7%
01/10/2013	>20.01K<30k	7	25%

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