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_6930 ( "Name" text, "Overs Bowled" real, "Maidens" real, "Runs Conceded" real, "Wickets" real, "Extras" real, "E.R." real )

### Question ###
What is the average Extras for Muttiah Muralitharan, with less than 353 Runs Conceded?

### Accurate SQL ###

SELECT AVG("Extras") FROM table_6930 WHERE "Name" = 'muttiah muralitharan' AND "Runs Conceded" < '353'