"If you are looking for fanfics, I can tell you I don't have any. But what I do have are a very particular set of skills, skills I have acquired over a very long career"
Just going by this you would assume that there has been some variance and that the overall usage has increased over time. However, in graph 2 we factor in the actual story length in a 2D scatter plot:
I really do hope ):( starts back up again soon.