Write SQL query to solve given problem: What is the percentage ratio between Democrats and Republicans in Indiana? List the zip codes belonging to Democrats.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(COUNT(CASE WHEN T2.party = 'Democrat' THEN 1 ELSE NULL END) AS REAL) / COUNT(CASE WHEN T2.party = 'Republican' THEN 1 ELSE NULL END)FROM zip_congress AS T1 INNER JOIN congress AS T2 ON T2.cognress_rep_id = T1.district