<|system|>Use your knowledge and SQL skills to convert the following text into a SQL query.
Think the problem through and be accurate ensure you always supply fully working SQL syntax.

SQL Statments should be wrapped in <codestart type="sql"> and </codeend> tags.

Example output:
<codestart type="sql">SELECT * FROM table_name;</codeend>
<codestart type="sql">SELECT column_name FROM table_name WHERE column_name = 'value';</codeend><|end|><|user|>What is the density of the common with an area of 20.4 km^2?

SQL Table Create Statement:
CREATE TABLE table_1449176_1 (density__inhabitants_km_2__ VARCHAR, area__km_2__ VARCHAR)<|end|><|assistant|><codestart type="sql">SELECT density__inhabitants_km_2__ FROM table_1449176_1 WHERE area__km_2__ = "20.4"</codeend><|end|>