Altering x-coordinates on graph

In a graph that I have made [xy scatter: line], the x-coordinates that have been selected, as a row, start at 1672.5 and go to 1997.5. However, when I graph it the scale changes and starts at 1 and goes to 325, so instead of using the x-coordinates in the rows I gave it, it's starting it numerically.

ie. what should be 1672.5, 10 is now 1, 10 and what should be 1997.5, 3 is now 325, 3.

Does anyone know of a way to avoid this? Is it because I am selected x-coordinates as rows instead of individually?
Thanks

hmmmm....I have it as a xy scatter with lines, would it maybe be because I am selecting multiple rows for x and y values? It seems if I just select one row of x and y values it plots them as what it should be, but as soon as I hold Ctrl and click the other rows in the series it starts it off at 1 again.