CREATE TABLE table_41454 ("Rank" TEXT, "Nation" TEXT, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

What is the sum of Silver when the total is less than 6, the rank is 6 and the Bulgaria is the nation?
SELECT SUM("Silver") FROM table_41454 WHERE "Total" < '6' AND "Rank" = '6' AND "Nation" = 'bulgaria'
SELECT SUM("Silver") FROM "table_41454" WHERE "Nation" = 'bulgaria' AND "Rank" = '6' AND "Total" < '6'