help with line chart

[latviankid]

I could use some help with the attached chart. The problem is that it's spacing each number on the bottom axis the same, and I need it to move the second number of each series closer to the first. For example, the gap in between 11 and 12 should be virtually nothing. on my chart, it should be dropping very sharp, almost straight up and down. I've checked everywhere, but can't find anything that addresses this problem.

Matt