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_16441 ( "Interregnum began" text, "Interregnum ended" text, "Duration" text, "Count Palatine of Saxony" text, "Count Palatine of the Rhine" text )

### Question ###
What is the number of interregnum for duration 3 months, 6 days?

### Accurate SQL ###

SELECT COUNT("Interregnum ended") FROM table_16441 WHERE "Duration" = '3 months, 6 days'