CREATE TABLE table_823 ("Aircraft type" CLOB, "National Origin" CLOB, "1st Flight" FLOAT, "In Service" CLOB, "Retired" CLOB, "# built" CLOB)

how many Curtiss XBTC aircraft are retired?
SELECT COUNT("Retired") FROM table_823 WHERE "Aircraft type" = 'Curtiss XBTC'
SELECT COUNT("Retired") FROM "table_823" WHERE "Aircraft type" = 'Curtiss XBTC'