Year	Number
1971	7220
1972	7493
1973	8345
1977	15000
1978	16142
1979	16308
1981	17030
1982	18751
1983	20769
1984	21903
1985	20286
1986	20756
1987	20884
1988	21410
1989	21031
1990	23107
1991	22236
1992	22474
1993	22396
1994	22544
1995	24575
1998	34114
1999	37440
2000	39754
2001	42914
2002	44960
2004	54721
2005	59434
2006	61932
2007	70389
2008	76558
2009	82753
2010	90236
2011	94798
2012	97717
2013	101372
2014	104051
2015	107976
2016	112730
2017	117065
2018	118743
2019	121488
2020	124777
2022	133644