LastNode and Filter issue

[Eric Hans van Wingerden 3]

I created a line chart with Avg([Price in USD]) on the Y axis and a Time Hierarchy on the X axis. The time hierarchy contains multiple years of data. Now, I want the Y axis not to display the Average price, but rather the Average Price as a percentage of the price in the last year. To do this I wrote this expression on the Y Axis:

 

Avg([Price in USD]) / Avg([Price in USD]) over (lastnode([Axis.X]))

Now, when I filter out the last year ALL my values disappear from the graph.... Is this per design Does the lastnode always go to the last node of the hierarchy regardless of the filter

Anyone knows a solution Your input would be appreciated!