Database: language_corpus
Question: What is the percentage of the words that have been repeated under 180 times in the Catalan language?
SQL: SELECT CAST(COUNT(CASE WHEN T2.occurrences < 180 THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.lid) FROM langs AS T1 INNER JOIN langs_words AS T2 ON T1.lid = T2.lid WHERE T1.lang = 'ca'