Question: How many series originally aired before 1999 with more than 7 episodes and a DVD Region 1 release date of 16 april 2013?
SQL: SELECT COUNT("Series Number") FROM "2-168334-1" WHERE "Original Air Date" < 1999.0 AND "Number of Episodes" > 7.0 AND "DVD Region 1 release date" = '16 april 2013';

Question: What's the latest original air date with more than 10 episodes and a DVD Region 2 release date of 23 april 2012?
SQL: SELECT MAX("Original Air Date") FROM "2-168334-1" WHERE "DVD Region 2 release date" = '23 april 2012' AND "Number of Episodes" > 10.0;

Question: What was the original air date of series number 10?
SQL: SELECT AVG("Original Air Date") FROM "2-168334-1" WHERE "Series Number" = 10.0;

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?
SQL: SELECT SUM("Number of Episodes") FROM "2-168334-1" WHERE "Original Air Date" > 1991.0 AND "Series Number" < 21.0 AND "DVD Region 2 release date" = '26 March 2012';

Question: What's the lowest series number that originally aired before 2009 with more than 7 episodes and had a DVD Region 2 release date of 26 july 2004?
SQL: SELECT MIN("Series Number") FROM "2-168334-1" WHERE "Original Air Date" < 2009.0 AND "DVD Region 2 release date" = '26 july 2004' AND "Number of Episodes" > 7.0;