Disclaimer: I haven't been very active the last year, and I didn't perform a statistical analysis on actual CV traffic data, thus I may definitely be wrong. However, I have the impression that the number of unanswered questions has risen with respect to last year. It has always been a sizeable fraction of the total questions, but now it seems larger to me. Am I correct? I guess it's pretty normal for a mature Q&A site. At some point, the site starts to become more of a database of good questions & answers, rather than a place where most of the new questions are answered (or closed as dupes).