What is the difference in the number of bad alias between Aguada city and Aguadilla city?
SUBTRACT(COUNT(bad_alias where city = 'Aguada'), COUNT(bad_alias where city = 'Aguadilla'));
SELECT COUNT(CASE WHEN T2.city = 'Aguada' THEN T1.bad_alias ELSE NULL END) - COUNT(CASE WHEN T2.city = 'Aguadilla' THEN T1.bad_alias ELSE NULL END) AS DIFFERENCE FROM avoid AS T1 INNER JOIN zip_data AS T2 ON T1.zip_code = T2.zip_code