Year	Number
1965	28749
1966	28986
1967	29307
1968	29695
1969	29936
1970	30257
1971	30671
1972	30907
1973	31182
1974	31374
1975	31568
1976	31685
1977	31728
1978	31670
1979	31524
1980	31016
1981	30399
1982	29606
1983	28965
1984	28693
1985	28583
1986	28733
1987	28664
1988	28674
1989	28394
1990	27949
1991	27996
1992	27725
1993	27544
1994	27426
1995	26887
1996	26636
1997	26600
1998	26625
1999	26971
2000	26956
2001	26980
2002	26985
2003	27083
2004	27333
2005	27629
2006	27754
2007	27981
2008	28231
2009	28551
2010	28814
2011	28997
2012	29241
2013	29129
2014	29305
2015	29551
2016	29688
2017	29916
2018	30072
2019	30132
2020	30235
2021	30432
2022	30467