CREATE TABLE table_name_51 (Id VARCHAR2)

What's the 1986 if 1991 has a QF and 1998 has a 3R?
SELECT 1986 FROM table_name_51 WHERE 1991 = "qf" AND 1998 = "3r"
SELECT 1986 FROM "table_name_51" WHERE "3r" = 1998 AND "qf" = 1991