Excuse me for not being objective, but a bit more interesting statistics of tags from Stack Overflow is here https://www.kaggle.com/c/predict-closed-questions-on-stack-o... (average and median reputation of persons posting questions, % of non-closed questions, average number of additional tags, median body length, freshness of the topic).

And my full project, Tag Graph Maps of Stack Exchange: https://github.com/stared/tag-graph-map-of-stackexchange/wik...