Question: The 2006–07 Four Hills Tournament was a series of ski jumping competitions held in the traditional venues of Oberstdorf, Garmisch-Partenkirchen, Innsbruck and Bischofshofen, located in Germany and Austria, before the tournament started on which date, the World Cup leader was Simon Ammann, a Swiss ski jumper?
Sentence (from "2006–07 Four Hills Tournament"): Before the tournament started on 28 December 2006 the World Cup leader was Simon Ammann.
Relevant evidence: Yes