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_16751596_13 (lead_maragin VARCHAR, dates_administered VARCHAR)
### Question:
On July 17, 2008, what was the total number of lead maragin? 
### Answer:
SELECT COUNT(lead_maragin) FROM table_16751596_13 WHERE dates_administered = "July 17, 2008"