Schema: CREATE TABLE table_24027047_1 (population_density___km²_2011_ VARCHAR, area__km²__2011 VARCHAR)
Question: What was the population density in km2 for 2011 in the division where area in km2 was 684.37 in 2011? 
SQL: SELECT population_density___km²_2011_ FROM table_24027047_1 WHERE area__km²__2011 * * = "684.37"