Year	Number
1960	11644
1961	11746
1962	11862
1963	11986
1964	12077
1965	12177
1966	12348
1967	12564
1968	12812
1969	13116
1970	13395
1971	13604
1972	13758
1973	13855
1974	13915
1975	13949
1976	13960
1977	13940
1978	13872
1979	13779
1980	13694
1981	13674
1982	13687
1983	13729
1984	13809
1985	13892
1986	13981
1987	14086
1988	14189
1989	14277
1990	14385
1991	14506
1992	14607
1993	14672
1994	14198
1995	13862
1996	14044
1997	14129
1998	14189
1999	14259
2000	14280
2001	14258
2002	14225
2003	14139
2004	13999
2005	13903
2006	13903
2007	13991
2008	14032
2009	14005
2010	13992
2011	13832
2012	13539
2013	13276
2014	13060
2015	12868
2016	12710
2017	12538
2018	12345
2019	12141
2020	11952
2021	11764
2022	11577