Nielsen Online today released its rankings of U.S. search share for April (PDF). Overall search increased 4.4 percent year over year to 8.6 billion searches. Google had year over year increase of 7.8 percent and received 64 percent of searches. Yahoo had a year over year decrease of 2.8 percent and received 16.3 percent of searches. Microsoft had a year over year increase of 7.2 percent and received 9.9 percent of searches.