Year	Number
1960	0
1965	0
1970	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1990	0
1996	1300
1997	1400
1998	1500
1999	8500
2000	22000
2001	25000
2002	38205
2003	46100
2004	54000
2005	86000
2006	110177
2007	112381
2008	136592
2009	134925
2010	167970
2011	176008
2012	127381
2013	114358
2014	120041
2015	176000
2016	180000
2017	184000
2019	184000
2020	184000
2021	184000