Year	Number
1971	772
1972	878
1973	949
1974	1024
1975	1100
1976	1252
1977	1377
1978	1577
1979	1813
1980	2037
1981	2029
1982	2303
1983	2508
1984	2798
1985	2871
1986	3154
1987	3141
1988	3732
1989	3980
1990	4037
1991	4286
1992	4598
1993	4917
1994	5656
1995	5853
1996	5864
1998	5679
1999	4648
2001	4961
2002	5201
2003	5684
2005	6298
2006	6639
2007	6791
2008	6248
2009	7544
2010	7374
2011	8421
2012	10566
2013	10677
2014	10478
2015	11221
2016	11971
2017	12435
2018	12649
2019	13093
2020	13131
2021	13077
2022	13159