Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_14981555_3 (jockey VARCHAR, date VARCHAR)
### Question:
How many different jockeys ran on 17 Feb 2007?
### Answer:
SELECT COUNT(jockey) FROM table_14981555_3 WHERE date = "17 Feb 2007"