CREATE TABLE table_56678 ("Rank" FLOAT, "Nation" TEXT, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

what is the rank when silver is less than 0?
SELECT SUM("Rank") FROM table_56678 WHERE "Silver" < '0'
SELECT SUM("Rank") FROM "table_56678" WHERE "Silver" < '0'