Year	Number
1970	20100
1971	20600
1972	21400
1973	21600
1974	19800
1975	16300
1976	18600
1977	12300
1978	9700
1979	8300
1980	8100
1981	12000
1982	13700
1983	14800
1984	16000
1985	21600
1986	23700
1987	24400
1988	22900
1989	23600
1990	20600
1991	20000
1992	25000
1993	24200
1994	25600
1995	26200
1996	24800
1997	28100
1998	27100
1999	24900
2000	26624
2001	28128
2002	28359
2003	27204
2004	29546
2005	30961
2006	33644
2007	37528
2008	39804
2009	44154
2010	48783
2011	57728
2012	62136
2013	68131
2014	71166
2015	83940
2016	94330
2017	99263
2018	110971
2019	119542
2020	72194
2021	99415