Year	Number
1973	1294
1974	1335
1976	1444
1977	1498
1978	1445
1979	1332
1986	5596
1987	6154
1988	6121
1989	7106
1991	8010
1992	7706
1993	6767
1994	10326
1995	9843
1996	10215
1999	11419
2000	12766
2001	13620
2002	12440
2003	13522
2012	18656
2013	19470