According to the report, the sales decline came from all across Asia. Net sales were down in Greater China (PRC, Taiwan & Hong Kong), Japan, and the Rest of Asia Pacific, while the Americas and Europe saw an insignificant change that can be rounded up to 0%.
This makes sense. Apple has its status as "the one and only smartphone" in the US, but in other countries buying a phone that costs a tiny fraction as much is probably a bigger draw and has less social stigma.