Below are links to ratings pages for 2014-15, 2015-16, 2016-17, and 2017–18. Tables and analysis have been provided by Bridger Cunningham. Enjoy!
2014-15: http://www.thetvratingsguide.com/1999/02/ratings-history-2014-15.html
2015-16: http://www.thetvratingsguide.com/1999/02/ratings-history-2015-16.html
2016-17: http://www.thetvratingsguide.com/1999/02/ratings-history-2016-17.html
2017-18: http://www.thetvratingsguide.com/1999/02/ratings-history-2017-18.html