CREATE TABLE table_48638 ("Official Name" TEXT, "Status" TEXT, "Area km 2" FLOAT, "Population" FLOAT, "Census Ranking" TEXT)

Notre-Dame-De-Lourdes has what average area km 2?
SELECT AVG("Area km 2") FROM table_48638 WHERE "Official Name" = 'notre-dame-de-lourdes'
SELECT AVG("Area km 2") FROM "table_48638" WHERE "Official Name" = 'notre-dame-de-lourdes'