The percentages are that country compared to the world (so both systems are much bigger sellers in the US, though probably just because of the much larger population).

GameCube Hardware (Launch through March 2004)
Japan - 3,460,000 (23.75%)
North America - 7,850,000 (53.88%)
Other - 3,270,000 (22.44%)
Total - 14,570,000

GameCube Software (Launch through March 2004)
Japan - 18,900,000 (17.52%)
North America - 64,580,000 (59.87%)
Other - 24,390,000 (22.61%)
Total - 107,870,000

Game Boy Advance Hardware (Launch through March 2004)
Japan - 13,210,000 (25.70%)
North America - 24,810,000 (48.29%)
Other - 13,380,000 (26.03%)
Total - 51,400,000

Game Boy Advance Software (Launch through March 2004)
Japan - 47,000,000 (25.57%)
North America - 96,470,000 (52.49%)
Other - 40,330,000 (21.94%)
Total - 183,790,000

Please tell me this wasn't posted already

Discuss. I will just point out that, for every GBA about 3.5 games are sold, but for every GC about 7.5 games are sold. Hmmm.