Question: What is Left Office, when Took Office is 2006?
SQL: SELECT "Left Office" FROM "2-16791908-1" WHERE "Took Office" = '2006';

Question: What is Left Office, when Party is Vacant (1999-2001)?
SQL: SELECT "Left Office" FROM "2-16791908-1" WHERE "Party" = 'Vacant (1999-2001)';

Question: What is Name, when President is Khamtai Siphandon, and when Left Office is 1999?
SQL: SELECT "Name" FROM "2-16791908-1" WHERE "President" = 'Khamtai Siphandon' AND "Left Office" = '1999';

Question: What is Party, when Name is Oudom Khattigna?
SQL: SELECT "Party" FROM "2-16791908-1" WHERE "Name" = 'Oudom Khattigna';

Question: What is Party, when Took Office is 1998?
SQL: SELECT "Party" FROM "2-16791908-1" WHERE "Took Office" = '1998';

Question: What is Left Office, when Took Office is 1998?
SQL: SELECT "Left Office" FROM "2-16791908-1" WHERE "Took Office" = '1998';