Year	Number
1974	21200
1975	26600
1976	27700
1977	28800
1978	34000
1979	63000
1980	51000
1981	57300
1982	69800
1983	74000
1984	92500
1985	102200
1986	127900
1987	159700
1988	176900
1989	159200
1990	196000
1991	190300
1992	200300
1993	261600
1994	325900
1995	397600
1996	493000
1997	470200
1998	510500
1999	547800
2000	572921
2001	840911
2002	932064
2003	946354
2004	1209900
2005	1349269
2006	1542564
2007	1753550
2008	1853088
2009	2140124
2010	2377789
2011	2538667
2012	2779741
2013	3073450
2014	3356756
2015	3616026
2016	3952098
2017	4359033
2018	4692008
2019	4963752
2020	3667920
2021	3906386