-- Database schema
| playstore : App [ TEXT ] , Category [ TEXT ] , Rating [ REAL ] , Reviews [ INTEGER ] , Size [ TEXT ] , Installs [ TEXT ] , Type [ TEXT ] , Price [ TEXT ] , Content Rating [ TEXT ] , Genres [ TEXT ] | user_reviews : App [ TEXT ] user_reviews.App = playstore.App , Translated_Review [ TEXT ] , Sentiment [ TEXT ] , Sentiment_Polarity [ TEXT ] , Sentiment_Subjectivity [ TEXT ] |
-- -- List down application that have not been updated since 2015. What is the percentage of this application having more negative sentiment than positive sentiment?

SELECT CAST((( SELECT COUNT(*) Po FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE SUBSTR(T1."Last Updated", -4, 4) > '2015' AND T2.Sentiment = 'Positive' ) - ( SELECT COUNT(*) Ne FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE SUBSTR(T1."Last Updated", -4, 4) > '2015' AND T2.Sentiment = 'Negative' )) AS REAL) * 100 / ( SELECT COUNT(*) NUM FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE SUBSTR(T1."Last Updated", -4, 4) > '2015' );