 The Tevatron was completed in 1983 at a cost of $120 million and significant upgrade investments were made in 1983–2011.The main achievement of the Tevatron was the discovery in 1995 of the top quark—the last fundamental fermion predicted by the Standard Model of particle physics.On July 2, 2012, scientists of the CDF and DØ collider experiment teams at Fermilab announced the findings from the analysis of around 500 trillion collisions produced from the Tevatron collider since 2001, and found that the existence of the suspected Higgs boson was highly likely with only a 1-in-550 chance that the signs were due to a statistical fluctuation.