Is the data available in the data explorer?
I haven't found it, so if it doesn't exist would we like to have it?
The development of the sites could be analysed there...
Area 51 is not available in the Data Explorer. The code and database running Area 51 are just too different from Stack Exchange to work with the current Data Explorer application. Area 51 started out based on Stack Exchange proper, but there are now too many differences to make it work under the same platform.
At this time, we're not likely to expend resources to develop an Area 51 Data Explorer. Area 51 isn't really a compilation of knowledge (that's why we're here), and the interest level would not warrant the resources needed to develop and maintain a completely new development project.