| | 1978 6 1997 9 | 1997 9 2000 6 | | 2000 6 2004 12 | | 2004 12 2007 1 | | 2007 1 2007 8 | | 2007 8 2011 8 | 2009 | 6 2009 12 | | 2011 8 2016 7 | | 2016 7 2018 8 | | 2018 8 2021 2 | 2019 12 | | 2021 2 2021 7 | | | 2021 7 | | |