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_2181798_1 (year VARCHAR, avg_finish VARCHAR)
### Question:
Name the number of years for 18.5
### Answer:
SELECT COUNT(year) FROM table_2181798_1 WHERE avg_finish = "18.5"