When did the oldest airline start operations?
CREATE TABLE table_15637071_1 (commenced_operations INTEGER)
SELECT MIN(commenced_operations) FROM table_15637071_1
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_15637071_1 (commenced_operations INTEGER) Question: When did the oldest airline start operations? [/INST] SELECT MIN(commenced_operations) FROM table_15637071_1 </s>