Year	Number
1970	12500
1971	31900
1972	39900
1973	38900
1974	42200
1975	46000
1976	60300
1977	46100
1978	47000
1979	48000
1980	39100
1981	29300
1982	18700
1983	20000
1984	20900
1985	21700
1986	22200
1987	21800
1988	22100
1989	24200
1990	22300
1991	20200
1992	23100
1993	24800
1994	23500
1995	26100
1996	26900
1997	28300
1998	29500
1999	34800
2000	40027
2001	44164
2002	46574
2003	52127
2004	66134
2005	75295
2006	75439
2007	75830
2008	78377
2009	78153
2010	72137
2011	61476
2012	44189
2013	54948
2014	48975
2015	38304
2016	43878
2017	50387
2018	70828
2019	44051
2020	9831.363
2021	11231