Here are some data from site analytics, regarding the last twelve months:
Traffic holds and has recently picked up strongly to historic highs:
...but voting exhibits a clear downward trend irrespective of traffic:
...while "Questions" also tend to slope downward :
Meanwhile, "Answers per Question" appear to have stabilized around $0.9$ :
Tentative Descriptive Summary: people keep coming but mainly to look and search existing content, while active participation is not satisfactory: voting falls, questions tend to fall, answers per question are not what they should be (ideally I would say it should be $2$ A's per Q, at least $1.5$ A's per Q).
Let's vote more - this is 2016 after all and many people are voting for something important in one country or the other. It is the aspect of site activity easiest to improve, and it has its way of helping the core Q & A function.