| | 1976 9 | | 1997 12 | 1998 09 | | | 1998.09 2002.05 | | 2002.05 2006.09 | 2005.03 2005.06 | | 2006.09 2007.12 | | 2007.12 2012.04 | | 2012.04 2015.04 | | 2015.04 2016.01 | | 2016.01 2017.09 | 2017.09 2020.01 | 2020.01 2020.06 | | 2020.06 20201.04 | | 2021.04 2021.07 | | 2021.07 2023.09 | | 2023.09— | | | | | |