Year	years
1970	13
1971	13
1972	13
1973	13
1974	13
1975	13
1976	13
1977	13
1978	13
1979	13
1980	13
1981	13
1982	13
1983	13
1984	13
1985	13
1986	13
1987	13
1988	13
1989	13
1990	13
1991	13
1992	13
1993	13
1994	13
1995	13
1996	13
1997	13
1998	13
1999	13
2000	13
2001	13
2002	13
2003	13
2004	13
2005	13
2006	13
2007	13
2008	13
2009	13
2010	13
2011	13
2012	13
2013	13
2014	13
2015	13
2016	13
2017	13
2018	13
2019	13
2020	11
2021	11
2022	11
2023	11