Search for technology dips

Out of curiosity I was checking the search trend for technologies. First I tried to search for MySQL and found that over the years the number of people who are searching for MySQL had been declining. Then I tried to compare with the oracle and ms access patterns and they too showed the pattern.

To explore more I searched for the trends of Linux, XML, Java , etc and the similarity was striking. The number of searches had steadily declined. Except for the mobile technologies the rest seems to have become less attractive for people to search about. Interesting - Is it because these technologies had matured? Or are they past their hour of spotlight. Not sure - Confusing!