Year	Number
1960	23164
1961	23476
1962	23709
1963	23888
1964	24045
1965	24239
1966	24516
1967	24866
1968	25250
1969	25620
1970	25996
1971	26371
1972	26587
1973	26539
1974	26272
1975	25811
1976	25359
1977	25003
1978	24557
1979	24002
1980	23413
1981	22949
1982	22658
1983	22426
1984	22202
1985	21973
1986	21877
1987	21965
1988	22103
1989	22302
1990	22564
1991	22942
1992	23416
1993	23817
1994	24113
1995	24271
1996	24469
1997	24743
1998	24920
1999	24977
2000	24901
2001	24925
2002	25083
2003	25167
2004	25165
2005	25084
2006	24951
2007	24830
2008	24722
2009	24607
2010	24524
2011	24503
2012	24543
2013	24618
2014	24667
2015	24732
2016	24765
2017	24906
2018	25326
2019	25832
2020	26190
2021	26350
2022	26374
2023	26349