Year	Number
1961	11390
1962	11445
1963	11506
1964	11574
1965	11667
1966	11791
1967	11921
1968	12042
1969	12122
1970	12118
1971	12116
1972	12091
1973	12033
1974	11983
1975	11952
1976	11994
1977	12102
1978	12225
1979	12389
1980	12556
1981	12720
1982	12887
1983	13041
1984	13218
1985	13417
1986	13628
1987	13847
1988	14035
1989	14223
1990	14496
1991	14815
1992	15072
1993	15315
1994	15592
1995	15922
1996	16205
1997	16386
1998	16568
1999	16796
2000	17031
2001	17178
2002	17208
2003	17317
2004	17419
2005	17467
2006	17505
2007	17554
2008	17608
2009	17672
2010	17814
2011	17883
2012	17808
2013	17615
2014	17174
2015	16571
2016	16272
2017	16528
2018	16690
2019	16745
2020	16893
2021	17085
2022	17117