| | | | | | | | | | — | 1968 10 | | | 1986 7 1990 | 1 | | | | | | 1986.07 1991.10 | | 1991.10 1993.03 | 1993.03 1997.03 | | 1993.03 1997.08 | | 1997.08 2001.03 | 2001.03 2009.10 | | 2009.10 2013.05 | | 2013.05 2018.05 | | | 2012.9 2017.10 | | 2018.05 2021.11 | | 2021.11 | | | | | | |