SAN FRANCISCO & DUBLIN--(BUSINESS WIRE)--In December Yahoo achieved its highest US search share for over five years according to the latest data from StatCounter, the independent website analytics provider. Google fell to the lowest monthly share yet recorded by the company*. These December stats coincide with Mozilla making Yahoo the default search engine for Firefox 34 users in the US. StatCounter Global Stats reports that in December Google took 75.2% of US search referrals followed by Bing