CREATE TABLE table_20615 ("#" FLOAT, "Series Sorted" TEXT, "Title" TEXT, "Author" TEXT, "Doctor" TEXT, "Featuring" TEXT, "Released" TEXT)

Name the total number of series sorted for when released is april 2010
SELECT COUNT("Series Sorted") FROM table_20615 WHERE "Released" = 'April 2010'
SELECT COUNT("Series Sorted") FROM "table_20615" WHERE "Released" = 'April 2010'