C# Adding to a list at runtime based off of list's name

I'm reading values in from a text file, instantiating a new instance of a class given the values that I'm reading in then trying to organize them in a series of lists. These lists are then stored in a sorted dictionary with a double as a key to return the list.

For example, I have a list declared as:

    List<DataPoint> Seventy = new List<DataPoint>();

I then may then read in a line 70.0, 43.2, 23.1, 235, 63, 43. My goal is to create an object - DataPoint - from the values that I'm reading in (which I know how to do) and then store that DataPoint in the "Seventy" List.

I think I have to use reflection, I'm just unsure of how to retrieve the list dynamically at runtime and continually append the DataPoint objects to the same list.

Thanks in advance!!