Year	Number
1971	361
1972	396
1973	533
1974	554
1976	756
1981	1292
1983	1617
1984	1607
1985	1997
1986	1901
1987	1808
1988	1777
1989	1764
1990	1900
1991	1995
1992	1894
1993	1771
1994	1737
1996	1508
1999	2381
2000	2536
2002	2660
2003	2908
2004	2967
2008	3685
2011	4201
2013	4322
2017	6429
2018	4428