Year	Number
1970	393
1971	537
1972	735
1973	806
1974	1054
1976	817
1977	1169
1978	1610
1979	1488
1980	1800
1981	2224
1982	2660
1983	3109
1984	3608
1985	3780
1992	4747
1993	5740
1994	7757
1995	10008
1996	12243
1997	15672
1998	18334
1999	21507
2000	25241
2001	28671
2002	31888
2003	34687
2004	38139
2005	41514
2006	44299
2007	47727
2014	72822
2015	72111
2016	72906
2017	73908
2018	74638