Write SQL query to solve given problem: Which current legislator has served for more terms, Sherrod Brown or Maria Cantwell?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CASE WHEN SUM(CASE WHEN T1.official_full_name = 'Maria Cantwell' THEN 1 ELSE 0 END) > SUM(CASE WHEN T1.official_full_name = 'Sherrod Brown' THEN 1 ELSE 0 END) THEN 'Maria Cantwell' ELSE 'Sherrod Brown' END FROM current AS T1 INNER JOIN `current-terms` AS T2 ON T1.bioguide_id = T2.bioguide