Followed the instruction to install contents stats. Regardless of a plugin type I am getting similar errors:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND st.component = "com_content" AND st.date_event BETWEEN SUBDATE(CURDATE(), 7' at line 1 SQL=SELECT COUNT(st.id) AS howmuch, st.date_event FROM drwzf_content_statistics as st LEFT JOIN drwzf_content as s ON s.id = st.reference_id WHERE st.type = 1 AND st.reference_id = AND st.component = "com_content" AND st.date_event BETWEEN SUBDATE(CURDATE(), 7) AND NOW() GROUP BY DAY(date_event), MONTH(date_event), YEAR(date_event) ORDER BY date_event

mysql - 5.5.33
php - 5.4.24