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_66 (low_estimate INTEGER, date VARCHAR)
### Question:
What is the sum of low estimate(s) that is listed for the date of 1978?
### Answer:
SELECT SUM(low_estimate) FROM table_name_66 WHERE date = "1978"