This chart shows how enormous of a yearly lead that the DS claimed from the PSP in 2006 and 2007, and how the PSP is now claiming back some of that territory, one teeny chunk at a time:


Notes:
1. Limitations noted in a previous post were circumvented by breaking each line and starting their zero point in the appropriate X point in time.

2. This method of presentation may be useful for any set of data with multiple years to be compared. It might be fun to replace the lines (in this case, white and red) with graphical representations of data, like a vertically-resized DS and a vertically-resized PSP to represent yearly gains.

3. More later.

PL