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_name_24 (year INTEGER, conventional_plans VARCHAR)
### Question:
How many years have a conventional plan of 7%?
### Answer:
SELECT SUM(year) FROM table_name_24 WHERE conventional_plans = "7%"