I want to change the numbering on a horizontal axis in a line graph. I want the axis to be numbered from 1945 to 2015. Currently it is numbered 1 to 63. Yes I know the numbers don't make sense, but I need some room on both ends of the graph to show that the data doesn't go farther than the line does. In short, I want to number the axis in years, not how many data points there are. Also, I am not good at using excel, so don't give me a link to some other website, it won't help me, give me step by step instructions please.