CREATE TABLE table_19179 ("Home  ( 1st leg ) " TEXT, "Home  ( 2nd leg ) " TEXT, "1st Leg" TEXT, "2nd leg" TEXT, "Aggregate" TEXT)

How many 2nd legs had an aggregate of 2-4?
SELECT COUNT("2nd leg") FROM table_19179 WHERE "Aggregate" = '2-4'
SELECT COUNT("2nd leg") FROM "table_19179" WHERE "Aggregate" = '2-4'