I just wanted to point out that the Games Data Library has added Famitsu sales data from 1988 to 1991. This means they now include the entire lifetime of the Super Famicom, Game Boy, and Megadrive, along with loads more Famicom data. They're the biggest source of info for this thread, so if you're curious about the historical sales of games in Japan, check them out!
https://sites.google.com/site/gamedatalibrary/