Event Comparisons is a great feature that lets you directly compare the registration progress of your event with a similar event from the past.  So you can see if you are ahead or behind schedule - and doing better or worse than last year.

First, you select a comparison event from the drop down list showing your other events.   

The graph will draw itself automatically and scale itself as best it can based on the numbers involved in each event.   The left (y) axis shows the number of registrants.   Active registrants - not pending or cancelled.

The horizontal (x) axis shows the # of days relative to day 1 of the event.  So the initial day of your event is cast for both events as "0".  The the head counts for each event are calculated based on registration #s, as they stood at times relative that "zero" time.    They are then superimposed over each other so they can be directly compared.

You can change the x-axis time frame by using the sliders to shrink or expand how much time is covered by the x axis.   If you are very interested in the last 4 weeks, for example, then change the "From" slider to "-28".