Season 1 ZDF Season 2005 ZDF , 2005 Season 2006 ZDF , 2006 Season 2011 ZDF , 2011 Season 2014 ZDF , 2014 Season 2016 ZDF , 2016 Season 2017 ZDF , 2017 Season 2018 ZDF , 2018 Season 2019 ZDF , 2019