One site statistic available through stackexchange.com or area51 is the % answered. On some sites, many unanswered questions get deleted after a month (if downvoted) or after a year (otherwise). Are those questions accounted for in the %answered?
For example, on Expats, it appears 70% of questions are deleted due to not getting answers (NB: the 70% estimate may be in error). The answer rate is supposed to be 84%. The two numbers do not really compute. How is this answer rate calculated when many questions get deleted, such as under the
I think it matters, because a site where most questions get no attention at all (lots of tumbleweed?) does not provide a good user experience. If, for example, only people who answer a question upvote the question, then the answer rate of questions will trend toward 100%, even if only a minority of questions get answered at all.