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_24674 ( "State Rank by Revenue" real, "Company Name" text, "National Rank" real, "Revenue ($billions) 2012 estimate" text, "Headquarters City" text, "Known for" text )

### Question ###
What is the national rank of Windstream?

### Accurate SQL ###

SELECT MIN("National Rank") FROM table_24674 WHERE "Company Name" = 'Windstream'