CREATE TABLE table_48925 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

Which Week has a Date of december 8, 1991?
SELECT AVG("Week") FROM table_48925 WHERE "Date" = 'december 8, 1991'
SELECT AVG("Week") FROM "table_48925" WHERE "Date" = 'december 8, 1991'