MDX Query for Min,Max and Median

Hi BI Gurus,

Just Now Stepping in to the unknown world of SSAS and just 30 days of theoritical training.I had build a Cube which holds metrics values as measures(SUM) linked to fiscal year,Metric Info and Security Info dimension.The Granularity of the record is Security-Metric-Year. Fiscal Year has got no hierachy in it except Year. How to extract min,max and median values for a given set of tickers for a given period (Say for eg:2010).I have tried the below query

WITH 
MEMBER [MEASURES].[MinValue]AS
MIN (descendants
(
[WSFYE].[Year].currentmember,[WSFYE].[Year]),
[Measures].[Metric Value]
)
SELECT
 {[MEASURES].[MinValue]} ON COLUMNS ,
 {[WS Info1].[SecurityName].children} ON ROWS
FROM [Thomson]
where 
({
[WS Info1].[Securityid].&[200230],
[WS Info1].[Securityid].&[B3XSX4],
[WS Info1].[Securityid].&[200230],
[WS Info1].[Securityid].&[269592],
[WS Info1].[Securityid].&[252015],
[WS Info1].[Securityid].&[201721],
[WS Info1].[Securityid].&[201354],
[WS Info1].[Securityid].&[207790],
[WS Info1].[Securityid].&[208510]},
[WS Item].[Name].[RETURN ON EQUITY - TOTAL (%)],
[WSFYE].[YEAR].[2010]
)

The above query gives me multiple o/p and but I need the minimum value for the selected securitries.Also how to build tht set dynamically