(This page will be updated monthly.)
US desktop search volume on a monthly basis from December 2004 to present (April 2016). Data is compiled from comScore qSearch and Nielsen//NetRatings MegaView Search reports.
April saw a huge 11.20% decrease, year over year, in US desktop search volume. In fact, the last time desktop search volume was lower was exactly five years ago in April of 2011!
We know that mobile search eclipsed desktop search, but it seems clear that mobile search continues to erode desktop query volume. In light of this, it makes perfect sense that Google would boost the weight for mobile friendly sites.
Go mobile or go home.