Has anybody made such analysis? It would be interesting to know the position of the majority of philosophers regarding metaphysics/mythology/religion, maybe by region and/or period.
According to the philpapers survey, 78% of the participating philosophers said they accept or lean towards atheism. 14% accept or lean towards theism, and the rest went into 'Other' with 12.6%. You can find the survey here: https://philpapers.org/surveys/results.pl
While it is difficult to put a firm date on it, more and more philosophers became atheists with the dawn of the scientific revolution and the subsequent waning of the Catholic Church's influence over philosophical thought. Some may date this as early as the 1500s or later (1700s). Suffice it to say that as science grew so did an atheistic outlook from philosophers. Now, of course, there were (and are) exceptions as there were ancient Greek philosophers who were atheist (Empedocles) and modern philosophers who were not (Antony Flew). There have been several surveys conducted, the validity of which can be debated endlessly. After reading a few of these surveys, I would put the percentage of atheist philosophers between 62-72%. The rest are roughly divided evenly between theists and "other".
Philosophers mentioned above (for further reading):
Demographics related to atheism can be found on Wikipedia: