Suggest an expression/filter please

Working on DMR model

Inserting the below data items in my chart from my cube

X-axis- [1990], [1991], [1992]
Measure – [Turnover rate]
Series- [Centers]

My centers is a hierarchy something like this

Centers
à Region
à Districts

Now I need to show Number of centers having turnover rate less than 25%

I tried using Total([Centers]) by replacing the original series [Centres] in chart but I get this error:
"The dimensions on the edge are inconsistent. The dimension of valueSet=“68” is not found on the first path"
I tried interchanging the position of data items in chart by placing both [Turnover rate] and Total([Centers]) in series, but I’m getting the same error

PLEASE HELP ME… I’M STUCK HERE FROM PAST 2 WEEKS

**Let me know if you need in any further information.
–Thanks in advance.