Display vertical gridlines on line graph

user10570

It would be great if there were an option to display vertical lines from the x-axis labels to allow users to easily see where the line graph intersects with each labelled point on the axis. Sharp turns in the data are fairly obvious, but datapoints that follow a trend are harder to see. Note in the graph attached the point on week 24 is difficult to determine. I could use display labels for the data points, but I don't want to detract from the line itself.