Year	Number
1973	557856
1974	561773
1975	561645
1976	556885
1977	503153
1978	502337
1979	485902
1980	468531
1981	450942
1982	434288
1983	415478
1984	398931
1985	385474
1986	376512
1987	373245
1988	375302
1989	383042
1990	394061
1991	404154
1992	414129
1993	443512
1994	447240
1995	461805
1996	477643
1998	522741
1999	529610
2000	538372
2001	537744
2002	536423
2003	535577
2004	532092
2005	524222
2006	517056
2007	510804
2008	505382
2009	499435
2010	492508
2011	487436
2012	483466
2013	483707
2014	483900
2015	490469
2016	498338
2017	507686
2018	514664
2019	521087
2020	527955
2021	533258
2022	538543