Year	Number
1970	9246
1971	9992
1972	10909
1976	15033
1980	21436
1981	23093
1982	24406
1983	25024
1984	25907
1985	27728
1986	29814
1987	33657
1988	34593
1989	35931
1990	38682
1991	42379
1992	46400
1994	48262
1995	47020
1997	56905
2000	74376
2001	79513
2002	82289
2003	89457
2004	94725
2005	96083
2006	98746
2007	107825
2008	117420
2009	125013
2010	128262
2011	131987
2012	136477
2013	139048
2016	142442
2017	150745
2018	153174
2019	153595
2020	154186
2021	156646
2022	158130