Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_991 ( "Name" text, "Population (2002 census)" real, "Population (2007 estimation)" real, "Population (2011 census)" real, "Area (km\u00b2)" text, "Density (pop/km\u00b2)" text )

### Question ###
What is the area in kilometers squared the population density is 137.61?

### Accurate SQL ###

SELECT "Area (km\u00b2)" FROM table_991 WHERE "Density (pop/km\u00b2)" = '137.61'