The prevalence of the seventh Android OS in the three months since its release reached 0.4%. The information was shared by Google.
Android Nougat was released in September 2016. By October, the OS was installed on 0.3% of devices. In November, this number increased by 0.1%.
Nougat is currently the second least popular Android operating system. In last place is 2.2 Froyo, which was released 6 years ago. This OS was installed on 0.1% of devices.
The 
most popular as of the end of November is Lollipop. The original version of this OS (5.0) was installed on 10.8% of devices, and the updated version (5.1) was installed on 23.2%.
The second most popular OS is Marshmallow with 26% of devices.
Source: Blog for Android Developers