1968 12 | 1988 | 7 1991 11 | | | 1988.07 1997.03 | | 1997.03 2001.07 | 2001.07 2002.10 | | 2002.10 2004.05 | | 2004.05 2005.05 | | 2005.05 2006.02 | | 2006.02 2007.04 | | 2007.04 2012.03 | 2007.8 2009.12 | | 2012.03 2016.07 | 2016.07 2020.01 | 2020.01 2020. 04 | | | | 2020.04 | | | | | | |