What percentage of no comment reviews are from "Teen" content rating apps?
no comment refers to Translated_Review = 'nan'; percentage = DIVIDE((SUM(Content Rating = 'Teen')), COUNT(*));
SELECT CAST(COUNT(CASE WHEN T1.`Content Rating` = 'Teen' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.App) FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE T2.Translated_Review = 'nan'
CREATE TABLE IF NOT EXISTS "playstore"
(
    App              TEXT,
    Category         TEXT,
    Rating           REAL,
    Reviews          INTEGER,
    Size             TEXT,
    Installs         TEXT,
    Type             TEXT,
    Price            TEXT,
    "Content Rating" TEXT,
    Genres           TEXT
);
CREATE TABLE IF NOT EXISTS "user_reviews"
(
    App                    TEXT
        references "playstore" (App),
    Translated_Review      TEXT,
    Sentiment              TEXT,
    Sentiment_Polarity     TEXT,
    Sentiment_Subjectivity TEXT
);
