Dynamic Named Ranges & Chart Series

Hi,

I'm just getting used to the idea of named ranges as chart series but I'm still confused as to how Excel determines which data to connect with lines.

Please see attached.

I would really like to chart the dotted black parallel lines you see on my chart as dynamic named ranges so it would be automatic no matter how many parallel lines there are (there's just 2 on the data sheet at present). I'm doing it manually, setting 21 seperate series, each with four data points, the X vaules are from column V & U and the Y values are from column S & T. Column V data should connect to Column S data and Column U data should connect to Column T data.

How does Excel determine which sets connect to which?

My attempt to do it with named ranges is the pink line (The last Series in the chart Data: Parallels) that looks nothing like the two dotted parallel lines. I'd like the pink line to replace the dotted ones. Can you see where I've strayed from logic's eternal path?

Any help is appreciated.

Thanks