Excel assumes you want to plot the horizontal axis as a date axis. Since you only have 12 data points over an 8-year time span the horizontal axis can hold almost 3000 data points. Then, the columns for each of the twelve plotted becomes very small. See picture.
Change the format of the axis type and set it to "Text axis" and you'll plot 12 same colored columns evenly spread in the chart area.
Edit: I had not seen the example data you provided nor your latest post where you discovered the Text axis option, until after I posted my answer. You can plot the x-axis in reverse order as your data starts with the most recent date at the top.