gHowl: Grasshopper - cleaning data

I’m trying to clean up my data in Grasshopper - which has been taken from Excel via gHowl.
As you’ll see from the first image below the data is listed in rows 0,1,2…0,1,2…0,1,2…etc.
Specifically, I’m keen to create a list of data (ie. 0,1,2,3,4,5,6,7,8,9…etc.) by ‘Splitting’ and ‘Culling’, so I can use the data to number to ‘extrude’ columns.
In the current format, it doesn’t work. Can you help?