Since 2013, Google has been saying 15% of queries are new and never seen before by Google. The interesting part, this is five years later and the stat has not changed. In 2007 it was 25% of queries, so it took a big bump down from 2007 to 2013, but since then, at least according to the Google speak, it is still at 15%.
Google’s John Mueller and Mariya Moeva mentioned the stat in their I/O session from last week. They said “we serve trillions of searches each year and out of those this is quite surprising for me every time I look at it about 15% of the queries every day are completely new ones things we’ve never seen before.” So it makes it sound like they looked again at the stat to see if this has changed, and it has not.
John Mueller of Google calls it a fascinating statistic:
Such a fascinating statistic! I wonder what was newly searched today?
— John ☆.o(≧▽≦)o.☆ (@JohnMu) May 12, 2018
Forum discussion at Twitter.