Thanks for the nice statistics!
Alan Turing Main Title Tournament 2012 has ended long before 3/20/2018 (the last game of it finished in 2015 iirc) but didn’t get marked as ended due to some bug. It was finally manually marked as finished in 2018. (As a weak evidence, the Alan Turing Main 2015 page has already listed the top-3 players for Alan Turing 2012)
Similarly, Honinbo Main Title Tournament 2014 has ended in 2017 (It was eventually marked as ended on 3/20/2018, the same day as Alan Turing Main Title Tournament 2012). A weak evidence is Honinbo Main 2017 has listed the top-3 for Honinbo 2014.