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_29803475_2 ( no_in_series INTEGER, us_viewers__million_ VARCHAR )

### Question ###
What is the lowest number in series when U.S. viewers is 0.23 million?

### Accurate SQL ###

SELECT MIN(no_in_series) FROM table_29803475_2 WHERE us_viewers__million_ = "0.23"