I made an interactive version of the above, with always up-to-date data, TagOverflow.
You can check tag grouping - i.e. for the sake of eliminating synonyms or poorly-defined tags.
Code and a more detailed description is on Github.
I notice that there are some members - especially those with very high 'scores' - who have 50x as many answers as questions.
Perhaps those members, who clearly know a lot, could be encouraged to ask questions for which they already know the answers. After all SE sites allow you to answer your own question.
Also, in case anyone feels it is being arrogant to ...