CREATE TABLE table_36340 ("Volume" TEXT, "Discs" FLOAT, "Episodes" FLOAT, "Region 1 release" TEXT, "Region 2 release" TEXT, "Region 4 release" TEXT)

What is the average episode that has September 11, 2007 as a region 1?
SELECT AVG("Episodes") FROM table_36340 WHERE "Region 1 release" = 'september 11, 2007'
SELECT AVG("Episodes") FROM "table_36340" WHERE "Region 1 release" = 'september 11, 2007'