More Excel Woes With Graphing

Once again Excel is giving me no end of trouble. It does not want to let me choose me x-axis values how I would like. Basically as you can see from the image Excel is assuming that all the values are evenly spaced from each other. e.g. 0.1, 0.2, 0.3, 0.4 etc. However this is not the case. The gap between the readings decreases at a certain point. (0.4, 0.5, 0.52, 0.54 etc.)

How can I make Excel aware of this?

ThanksAttachment 68770

I'm not sure if this belongs in this forum but you need to choose a scatter plot rather than a line graph.