I am looking at the number of community wiki questions and answers over time. Making a question community wiki automatically transforms all of its answers to community wiki also. Thus, I remove those answers from the analysis (for the answer figure) whose parent questions are also community wiki. Interestingly, I find sharp drops in questions after July 2010 and after March 2014. After some investigation, I find that in April 2014, all automatic triggers for community wiki were stopped. While this explains the drop-2 in wiki questions but I could not find any reason for drop-1. Similarly, I also observe some interesting cases for wiki answers (see drop-1, drop-2 and a sudden increase in wiki answers). Can anyone shed light (possible explanation) on these cases?