Google has never revealed what number of devices have been moved up to the most recent Android 10 version in the previous year, however, Google released a comparison of active users of a few versions of Android this morning. The data shows that the update speed of Android 10 is quicker than that of every single past version of Android. Android 10 has secured 100 million devices within 5 months after its discharge (28% quicker than Android 9).
Tuyuan Google Android Developer Blog
The report released by Google I/O 2019 shows that there were about 2.5 billion Android active devices at that time, and Google announced in August last year that Android 9 was installed on about 22.6% of Android devices. Google subsequently officially released Android 10 on September 3. According to foreign media androidauthority, it is conservatively estimated that Android 10 is currently running on 15% of Android devices, and this number may have reached 400 million.
Screenshot of Apple developer website