What is the campus fee for San Francisco State University in 1996?
SELECT campusfee FROM campuses AS T1 JOIN csu_fees AS T2 ON T1.id  =  t2.campus WHERE t1.campus  =  "San Francisco State University" AND T2.year  =  1996
campus fee refers to campusfee; San Francisco State University refers to filtering campuses by campus name; in 1996 refers to filtering by year = 1996; JOIN is used to link campuses and csu_fees tables on a common identifier;