Table:
text: List of longest-serving G8 leaders
Chronology of longest serving G8 Leaders
Chronology of longest serving G8 Leaders
Entered_office_as_Head_of_State_or_Government Began_time_as_senior_G8_leader Ended_time_as_senior_G8_leader Person Office
20 January 2001 7 May 2008 20 January 2009 George W. Bush President of the United States
10 May 1994 20 January 2009 16 November 2011 Silvio Berlusconi Prime Minister of Italy
22 November 2005 16 November 2011 7 May 2012 Angela Merkel Chancellor of Germany

Question: When did the Italian Prime Minister take office on the list of longest-serving G8 leaders?