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_21258_1 (infant_mortality_rate INTEGER, period VARCHAR)
### Question:
period between 1985 - 1990 have minimum infant mortality rate of what.
### Answer:
SELECT MIN(infant_mortality_rate) FROM table_21258_1 WHERE period = "1985 - 1990"