I have data in two columns. I've included some of the values (not all, for
the sake of brevity) below.

3.6 0.1
6.4 0.1
7.4 0.2
10.0 0.1
10.4 0.1

The first column is to be plotted on the X axis. I've tried different kinds
of charts (Line and Scatter). However, every value on the Y axis shows up
twice. The Y axis looks like this:

0.3______________________________________
0.3______________________________________
0.2______________________________________
0.2______________________________________
0.1______________________________________
0.1______________________________________

Any idea why this happens? Also, how do I get Excel to stop showing every
marker on the Y axis twice?

Thanks in advance!