List of world number one snooker players

Columns: No | Nationality | Player | From | To
7 | England | Ronnie O'Sullivan | 7 May 2002 | 5 May 2003 | Wales | Mark Williams ( 2 ) | 6 May 2003 | 3 May 2004 | England | Ronnie O'Sullivan ( 2 ) | 4 May 2004 | 1 May 2006 | Scotland | Stephen Hendry ( 2 ) | 2 May 2006 | 7 May 2007 | Scotland | John Higgins ( 2 ) | 8 May 2007 | 5 May 2008 | England | Ronnie O'Sullivan ( 3 ) | 6 May 2008 | 3 May 2010 | Scotland | John Higgins ( 3 ) | 4 May 2010 | 26 September 2010

Example questions:
How many times was the person who became the top ranked snooker player in the world in 1983 a world champion ? | What does the British Broadcasting Company currently employ the person who became the top ranked snooker player in the world in 1990 as ? | How many career century breaks have been accumulated by the person who became the top ranked snooker player in the world in 2003 ? | How much has the person who became the top ranked snooker player in the world in 2002 earned from snooker tournaments ?

Answers:
six | commentator | 470 | £11 million