From arstechnica Mac OS X North American installed base almost 11%:
Mac OS X only accounts for about 2.5 percent of users in Asia. The two most populous countries in the world, China and India, have an even lower percentage overall—1.9 and 1.2 percent, respectively. Japan is likely responsible for the majority of Mac OS X share in that region.
Considering how America-centric Apple is, it does not surprise me one bit that they will be more successful there than in other parts of the world. Note that I think much of this apparent America-centrism is due to Apple’s vertical market strategy which includes distributing media for its devices. The large media distribution companies that Apple must deal with remain stuck in a pre-Internet age, much to the detriment of foreign consumers and customers. So, I don’t put all the blame on Apple, and I don’t think they are “anti-foreign” by any means. If anything, rather than favouring one culture over another, I think Apple has always been about promoting its own culture.