CREATE TABLE table_19514 ("DVD name" TEXT, "Ep No." FLOAT, "DVD No." FLOAT, "Release date" FLOAT, "Additional information" TEXT)

How many release dates does volume 4 DVD have?
SELECT COUNT("Release date") FROM table_19514 WHERE "DVD name" = 'Volume 4'
SELECT COUNT("Release date") FROM "table_19514" WHERE "DVD name" = 'Volume 4'