Year	Number
1971	23504
1972	23718
1973	26405
1974	27754
1975	29532
1976	30603
1977	32247
1978	34121
1979	34372
1980	35742
1981	24027
1982	30057
1983	29905
1984	29843
1985	34608
1986	37630
1987	35878
1988	34951
1989	34248
1990	33289
1991	33561
1992	35535
1993	30016
2001	41874
2002	42253
2005	45818
2006	46725
2007	47235
2008	48134
2009	47221
2010	50164
2011	49563
2012	50868
2013	52109
2014	51784
2015	54721
2018	58408
2020	56566
2021	50494