CREATE TABLE table_43596 ("Name" TEXT, "Hanzi" TEXT, "Hanyu Pinyin" TEXT, "Population  ( 2004 est. ) " TEXT, "Area  ( km\\u00b2 ) " TEXT, "Density  ( /km\\u00b2 ) " TEXT)

What is the 2004 population for ?
SELECT "Population (2004 est.)" FROM table_43596 WHERE "Hanzi" = '昌黎县'
SELECT "Population (2004 est.)" FROM "table_43596" WHERE "Hanzi" = '昌黎县'