Write SQL query to solve given problem: How many times is the number of keywords in "Refuge: Part 1" episode than "Shield" episode?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(CASE WHEN T1.title = 'Refuge: Part 1' THEN 1 ELSE 0 END) AS REAL) / SUM(CASE WHEN T1.title = 'Shield' THEN 1 ELSE 0 END) FROM Episode AS T1 INNER JOIN Keyword AS T2 ON T1.episode_id = T2.episode_id