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_1015421_1 (year_built VARCHAR, no_built VARCHAR)
### Question:
What year was number 7 built?
### Answer:
SELECT year_built FROM table_1015421_1 WHERE no_built = 7