user: ### NOW ANSWER:
Question: What is the USN 2013 ranking with a BW 2013 ranking less than 1000, a Forbes 2011 ranking larger than 17, and a CNN 2011 ranking less than 13?
Columns: ['Location (State, City)', 'USN 2013', 'BW 2013', 'Forbes 2011', 'Ec 2013', 'FT 2011', 'AE 2011', 'CNN 2011', 'BI 2013', 'ARWU 2012']
Types: ['text', 'real', 'real', 'real', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Alabama, Auburn', 75.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0, 1000.0]
SQL:

assistant: SELECT SUM("USN 2013") FROM "Table" WHERE "BW 2013" < 1000.0 AND "Forbes 2011" > 17.0 AND "CNN 2011" < 13.0;