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_52221 ( "County" text, "1900" real, "1930" real, "1950" real, "2000" real, "2006 est." real )

### Question ###
What is the 1930 population when the 2006 est. is less than 44,726 in the county of frio?

### Accurate SQL ###

SELECT SUM("1930") FROM table_52221 WHERE "2006 est." < '44,726' AND "County" = 'frio'