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_203_222 ( id number, "category" text, "#" number, "name" text, "hanzi" text, "hanyu pinyin" text, "population (2010 census)" number, "area (km2)" number, "density (/km2)" number )

### Question ###
what is the difference in population between enping and heshan ?

### Accurate SQL ###

SELECT ABS((SELECT "population (2010 census)" FROM table_203_222 WHERE "name" = 'enping') - (SELECT "population (2010 census)" FROM table_203_222 WHERE "name" = 'heshan'))