Year	Number
1970	110372.6
1971	112201.2
1972	117171.6
1973	119712.3
1974	119008.9
1975	126061.1
1976	126223.4
1977	128299.9
1978	133632.3
1979	138397.3
1980	146083.7
1981	148513.3
1982	150613.4
1983	154620.1
1984	157763.5
1985	162994.9
1986	164812.6
1987	158308.2
1988	157181
1989	153325.6
1990	160940
1991	160227.3
1992	158985.8
1993	148870.9
1994	147335.5
1995	148575.1
1996	136163.7
1997	140195.2
1998	133518.1
1999	134819.4
2000	141849.5
2001	150511.2
2002	155843.9
2003	159260.2
2004	173022.4
2005	180906.5
2006	176238.7
2007	174603.9
2008	168025.1
2009	168662.6
2010	165491.9
2011	161112
2012	162677
2013	163835.3
2014	164628.4
2015	167582.4
2016	178218.6
2017	179972.6
2018	183018.4