Percentage Difference

My data set has 6 months of data. I want to show 2 additional columns in the visualization: 

1) the current month's percentage change from the previous month

2) The current month's % change vs 6 months ago

On the left is my input data, and on the right is the current visualization.

I have played with the MoM quick measure unsuccessfully.  Note I do not want these "measures' for each month of the month's I am showing...I just want it for the most recent month.  

Thanks as always!