Analysis :: Count Of Rows In SSAS MDX Query

I need to find the percentile using cube so i am using the below formula :

((n-1) * p /100) -1

n= count of number of array records
p= percentile

I am using below MDX query:

WITH MEMBER [Measures].[PV] AS 25
Member [Measures].[CntCT] as Count(NonEmpty([Tb City].[City Name].&[DC], [Measures].[CPT1]))
Member [Measures].[PVInt25] as  Int(((([Measures].[CntCT] - 1)* [Measures].[PV])/100) - 1)
Member [Measures].[PVC] as ([Measures].[CPT1],Order(NonEmpty([Tb City].[City Name].&[DC],[Measures].[CPT1]),
[Measures].[CPT1],ASC).Item([Measures].[PVInt25]))

Select [Measures].[PVC] on columns, {[Tb City].[City Name]} on rows from test;

The line 2:
Member [Measures].[CntCT] 

In that i need to find the n count of rows where city is DC (City is my Dimension) in Measures CPT1

But currently it is giving the result 1 instead in actual in my test cube there is the city DC exists with 23 CPT1 rows count.

I tried the below query:

SELECT NON EMPTY {[Tb City 1].[City Name].[City Name].&[DC]  } 
   ON COLUMNS, NON EMPTY { ( [Measures].[Tb Main Count] ) }
 ON ROWS FROM [test]

Above query gives me the correct count i.e. 23 but i need to get the result of above query in line 2 of MDX query:

Member [Measures].[CntCT]