I don’t know of any broader, larger trends. It is worth noting here that the Rabbis of the Talmud themselves thought that the prior texts (especially the Torah itself) were infallible, so it seems that part of what might be happening is that over time, more and more gets put into the very-holy-text category.
Also, it seems important to distinguish here between being unquestionably correct with being literal. In a variety of different religions this becomes an important distinction and often a sacrifice of literalism is in practice made to preserve correctness of a claim past a certain point. Also note that in many religious traditions, the traditions which are most literal try to argue that what they are doing is not literalism but something more sophisticated. For example, among conservative Protestants it isn’t uncommon to claim that they are not reading texts literally but rather using the “historical-grammatical method.”
This should not be reported this way. It should be reported as something like 66%. The other digits are not meaningful.