Year	years
1971	2
1999	2
2000	2
2001	2
2002	2
2003	2
2004	2
2005	2
2006	1
2007	1
2008	1
2009	1
2010	1
2011	1
2012	1
2013	1
2014	1
2015	1
2016	1
2017	1
2018	1
2019	1
2020	1
2021	1
2022	1
2023	1