If you did something like this you could show the annual or monthly sums or averages along with the running totals. You can create a parameter and put the different aggregations in it. Use the user selected aggregation to modify the view. My putting the commodity on color you can separate them out.
You could also place the domestic export dollars on size and change the line size depending on the percent total of all exports for the month or year.
Caitlyn Garger there are other options, as well. In the spirit of Tim Dines' suggestion above, you could include your graph of dollar v. dollar, but also include 2nd axis showing Percent Change (the quick calculation).
This might uncover unexpected synchronicities lost in the current graph.
To avoid your graph becoming too busy with lines, you could have the viewer switch between views; you could split it into a second graph (with on hover highlighting); or you could include a graph-in-tooltip.
Good Luck & Happy Vizzing!