What's the sum of the number of episodes that originally aired after 1991 with a series number smaller than 21 and a DVD Region 2 release date of 26 march 2012?
CREATE TABLE table_name_99 (number_of_episodes INTEGER, dvd_region_2_release_date VARCHAR, original_air_date VARCHAR, series_number VARCHAR)
SELECT SUM(number_of_episodes) FROM table_name_99 WHERE original_air_date > 1991 AND series_number < 21 AND dvd_region_2_release_date = "26 march 2012"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_99 (number_of_episodes INTEGER, dvd_region_2_release_date VARCHAR, original_air_date VARCHAR, series_number VARCHAR) Question: What's the sum of the number of episodes that originally aired after 1991 with a series number smaller than 21 and a DVD Region 2 release date of 26 march 2012? [/INST] SELECT SUM(number_of_episodes) FROM table_name_99 WHERE original_air_date > 1991 AND series_number < 21 AND dvd_region_2_release_date = "26 march 2012" </s>