CREATE TABLE table_12916 ("Club" TEXT, "City" TEXT, "Founded" FLOAT, "Stadium" TEXT, "Capacity" FLOAT)

How many foundeds have stade tunisien as the club, with a capacity greater than 18,000?
SELECT SUM("Founded") FROM table_12916 WHERE "Club" = 'stade tunisien' AND "Capacity" > '18,000'
SELECT SUM("Founded") FROM "table_12916" WHERE "Capacity" > '18,000' AND "Club" = 'stade tunisien'