Explanations / Notes:
The default BarHeightFactor of 5 means 5 pixels of height for a million systems shipped. Since software shipments are much higher, I recommend something more like 0.5 if making a software comparison.
The Sony systems with "old" at the end are from their older method of reporting "shipped from factories" rather than "shipped to retailers" as they do now. PS1 is this way as well, however since there is no "new" data I didn't specifically mark it as old.
Technically, it doesn't make sense to list 0 systems as having shipped on launch day. But for our purposes here I think it's an acceptable fiction that beats not having the launch day marked.
GB includes the sum of GB+Pocket+Light+Color. GBA includes the sum of GBA+GBASP+GBM. DS includes the sum of DS+DSL+DSi+DSiLL.
Note that minor regions often get lumped with the major ones. Japan might include Asia, Europe might include Australia. It may even differ from manufacturer to manufacturer, so if I'm good I should add such information here in the future.
There are some pretty huge gaps in the data before the mid-late-1990s. If you ask for an NES/SNES/GB number from before that time, you'll just get the most recent number it has: 0. Quite incomplete, but stick to letting it use the most recent numbers and they make for fine comparisons with more recent systems.
I tried to use announced LTDs whenever possible. When only quarterly/yearly information was available, I add/subtract from available data and do something like add 1 to mark it as different; the company might have rounded things slightly differently.