Apple's market share in China has reportedly fallen by 26.6% in 2018. Unsurprisingly, the culprits are more 'local' OEMs such as Huawei and Xiaomi, who offer more innovative features in premium handsets that go for less than those from the Cupertino company.
https://www.notebookcheck.net/Apple-is-losing-its-majority-in-the-Chinese-smartphone-market.414965.0.html