The data is not clear about that. If I had taken this survey, my response to the following question would make you think that this was my first functional language, when in fact I have been exploring exotic languages for about five years.
"What language did you use just prior to adopting Clojure – or, if Clojure is not your primary language now, what is that primary language?"
Clojure is my favorite language right now and, if I had taken the survey, I would have answered "Java" because that is what I use for most of the day at my job. However, I have also used almost every language on that pie chart (except for Ada and C#) and would prefer almost any of those over Java (except for C, C++, and C#) if other people were not involved in the choice of my primary language.
Fortunately, I have successfully lobbied to have Clojure included in my workplace. I am very much enjoying the transition away from Java.