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_10528691_4 (model INTEGER, introduction VARCHAR)
### Question:
What is the model number introduced May 1999?
### Answer:
SELECT MAX(model) FROM table_10528691_4 WHERE introduction = "May 1999"