CREATE TABLE table_203_466 (id DECIMAL, "rank" DECIMAL, "nation" TEXT, "gold" DECIMAL, "silver" DECIMAL, "bronze" DECIMAL, "total" DECIMAL)

the nation before mexico in the table
SELECT "nation" FROM table_203_466 WHERE id = (SELECT id FROM table_203_466 WHERE "nation" = 'mexico') - 1
SELECT "nation" FROM "table_203_466" WHERE "id" = (SELECT "id" FROM "table_203_466" WHERE "nation" = 'mexico') - 1