Line Charts Are Confusing

Created with Highcharts 4.2.3 /Highstock 4.2.3I Have No Idea What I'm DoingNumbers!purple lineGDP of Slovakia?A Third Line!20011984Wait, this is wrongFebruary 31st012345
purple lineGDP of Slovakia?A Third Line!
2001113
1984232
Wait, this is wrong002
February 31st40.50
I Have No Idea What I'm Doing
Numbers!