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_54 (year VARCHAR, hmos VARCHAR, pos_plans VARCHAR)
### Question:
How many years have HMOs been 27% and POS plans 18%?
### Answer:
SELECT COUNT(year) FROM table_name_54 WHERE hmos = "27%" AND pos_plans = "18%"