MDX Count( EXISTING ....)

i have the following :

- employees dimension
- projects dimension
- date dimension
- fact table contains the number of hours an employee worked on a project on a certain date

+ i want to find the number of employees worked on each project; so i wrote the following MDX:

 with member [Measures].[Number of Emps] as  count(EXISTING [D TC Employee].[Name].members)
 select [Measures].[Number of Emps] on 0,
 [project].[project Id].[Level 02].members on 1
 from [TC Cube]

in the result, for each project I'm getting 942 as "Number of Emps" and this is wrong and i don't know why ! what is wrong with the query ?!