What does the line on the bottom means of the Chart of all fuel-ups

[scootinChris]

When I show the chart of all fuel-ups, there is a line in between two date axis. What does it signifies? There is no vertical axis for it

Thank you.

[kstinmb]

Same question. What is this showing?


Thanks,
-stephen

[Matt715]

Maybe it's just the same graph with smoothing applied?

[RobertV]

It allows you to select (click and drag) a range to view on the top graph.
Ex: If you want to see only 2014 data- On the bottom graph, click Jan '14 and drag all the way to the right to select all of 2014 fill-ups. The Top graph will then reflect only the selected.