Year	Number
1975	13256
1976	12829
1977	12395
1978	12455
1979	12572
1980	15559
1981	15610
1982	15273
1983	16018
1984	16794
1985	17252
1986	18166
1987	19319
1988	18944
1989	18728
1990	18375
1991	19097
1992	19082
1993	20061
1994	20571
1995	21975
1996	22910
1997	23260
1998	23947
1999	24399
2000	25972
2001	26454
2002	26150
2003	28490
2004	25987
2005	26286
2006	30363
2007	30805
2008	30201
2009	29210
2010	28972
2011	29459
2012	28793
2013	29861
2014	30072
2015	28178
2016	27790
2017	27175
2018	27126
2019	26817
2020	27427
2021	29403
2022	26550