How many years did BBC One rank 20th?
CREATE TABLE table_103084_4 (year VARCHAR, bbc_one_rank VARCHAR)
SELECT COUNT(year) FROM table_103084_4 WHERE bbc_one_rank = "20th"
### Context: CREATE TABLE table_103084_4 (year VARCHAR, bbc_one_rank VARCHAR) ### Question: How many years did BBC One rank 20th? ### Answer: SELECT COUNT(year) FROM table_103084_4 WHERE bbc_one_rank = "20th"