CREATE TABLE torrents (groupname TEXT, totalsnatched DECIMAL, artist TEXT, groupyear DECIMAL, releasetype TEXT, groupid DECIMAL, id DECIMAL)
CREATE TABLE tags (index DECIMAL, id DECIMAL, tag TEXT)

Which year has the most released song?
SELECT groupyear FROM torrents GROUP BY groupyear ORDER BY COUNT(groupname) DESC LIMIT 1
SELECT "groupyear" FROM "torrents" GROUP BY "groupyear" ORDER BY COUNT("groupname") DESC NULLS LAST LIMIT 1