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_1555308_1 (prothrombin_time VARCHAR, platelet_count VARCHAR)
### Question:
How many entries for prothrombin time are there where platelet count is "decreased or unaffected"?
### Answer:
SELECT COUNT(prothrombin_time) FROM table_1555308_1 WHERE platelet_count = "Decreased or unaffected"