Year	Number
1971	542445
1972	528247
1973	514002
1974	501299
1975	484590
1976	495645
1977	507375
1978	522639
1979	528362
1980	521279
1981	523156
1982	543644
1983	556037
1984	571611
1985	579356
1986	567615
1987	570809
1988	552520
1989	529094
1990	478887
1991	455888
1992	439637
1993	429594
1994	423818
1995	425286
1996	433926
1997	431790
1998	425511
1999	411726
2000	392876
2001	374361
2002	349616
2003	333016
2004	314221
2005	290017
2006	273045
2007	267584
2008	262701
2009	261007
2010	260340
2011	255086
2012	252372
2013	253675
2014	258840
2015	261793
2016	261969
2017	264503
2018	262735
2019	256857
2020	248354
2021	237737