90 Day Sales Moving Average

[johny.cbi]

Display 90 Days Data in Sparkline Chart (eg;- current Month, Current Month-1, current Month-2)
The data is coming from cube (MDX)

I've Measure(Y-Axis)
expression on Y-AXIS

average([Sales Cube].[Measures].[Sales Amount] within set filter(lastPeriods(90,currentMember([Sales Cube].[Date].[Date])), tuple([Sales Cube].[Measures].[Sales Amount],currentMember([Sales Cube].[Date].[Date]))<>0))

I am using the following expression on X-AXIS

tail([Sales Cube].[Date].[Date].[Day],160)

with this result is coming wrong

my question is

I need the data for 90 days (current Month, Current Month-1, current Month-2) on X-AXIS