Use an "X-Y (Scatter)" chart instead of a "Line" chart.
The "Line" chart is misleadingly named. It has nothing to do with
whether you want a line or not. A "Line" chart would be more accurately
called a "category" chart, since the x-axis represents equally spaced
categories (labeled 1,2,3,... by default) instead of an arithmetic scale.
If you really want a non-arithmetic scale labeled with numbers starting
at zero, then supply your own labels in a range to the "Line" chart.
Jerry