Sales Curve 2 weeks prior to event

Hello!

I am a Tessitura analytics newbie. I am trying to create a sales curve graph with the number of tickets sold in the last two weeks leading up to an event. When I filter for 14 days prior to the event, the ticket count starts at 0. Is it possible to have the ticket count begin at the amount of tickets which were previously sold? In the example below, the second graph should start at 178 tickets instead of 0.

Thanks so much!

Here is a graph of all sales:

Here is a graph of the last two weeks leading up to the event.: