CREATE TABLE table_name_16 (Id VARCHAR2)

Which 2008 had a 1998 and 2006 that were a when 2009 was sf?
SELECT 2008 FROM table_name_16 WHERE 1998 = "a" AND 2009 = "sf" AND 2006 = "a"
SELECT 2008 FROM "table_name_16" WHERE "a" = 1998 AND "a" = 2006 AND "sf" = 2009