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_51 ( "Year" real, "Aircraft kilometers" real, "Departures" real, "Flying hours" real, "Passengers" real, "Seat factor" text, "Employees" real, "Profit/loss" text )

### Question ###
What percentage of seats were filled in 2006?

### Accurate SQL ###

SELECT "Seat factor" FROM table_51 WHERE "Year" = '2006'