CREATE TABLE table_51955 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What is the least amount of people that attended a game when Essendon was the away team?
SELECT MIN("Crowd") FROM table_51955 WHERE "Away team" = 'essendon'
SELECT MIN("Crowd") FROM "table_51955" WHERE "Away team" = 'essendon'