Year	Number
1980	22699
1981	23267
1982	23883
1983	23690
1984	24709
1985	25482
1986	25596
1987	26598
1988	28869
1989	32060
1990	24375
1991	21097
1992	22950
1993	23307
1994	24683
1995	24161
1996	24987
1997	25238
1998	30163
1999	33189
2000	35435
2001	35753
2002	35782
2003	33299
2004	32970
2005	34705
2006	36516
2007	35133
2008	37028
2009	32410
2010	30899
2011	30357
2012	30533
2013	30174
2014	31283
2015	32687
2016	30667
2017	30969
2018	31812
2019	32250
2020	30113
2021	32445