Unable to display the top 10 items in a Bar Graph in ssrs 2008 r2

Hi ,

I am running a query to fetch top 10 items and display using a bar graph. When I create a data set and try to bring up in SSRS . i do not see 10 items it shows me only 5 in Y Axis. however if i modify the query and say fetch top 9 items i am able to see all the items in the Y Axis.

My query

SELECT top 10 count(distinct coulumnname) as 'XYZ',item
FROM Atable WHERE date BETWEEN '2012-01-01 0:0:0' AND getdate()
AND condition1 AND condition1 
group by item
ORDER BY XYZ DESC