How healthy is our stack exchange compared to others?

Question

For October 2015

Are there statistics available telling us whether we have more or less number of unanswered questions compared to other stack exchanges, and is there a metric available that ascertains whether our stack exchange is healthy or unhealthy in any regards?

Answer 1

Stack Overflow
--------------

Questions  Accepted   >= 1 answers  Closed (Ex Deleted)
10386638   5819260    9148900       443261

Here, 56% of questions have an accepted answer and 88% have 1 or more answer (i.e. 12% have no answers). 4% are closed.

Ask Ubuntu
----------

Questions  Accepted   >= 1 answers  Closed (Ex Deleted)
204114     69534      162546        27566

Here 34% of questions have an accepted answer and 80% have one or more answer (i.e. 20% have no answers). 14% are closed.

Unix and Linux
--------------

Questions  Accepted   >= 1 answers  Closed
75899      38258      64049         4988

Here 50% of questions have an accepted answer and 84% have one or more answer (i.e. 16% have no answers). 7% are closed.

My pronouns are He / Him