Year	Number of
1980	1058
1981	1170
1982	497
1983	2029
1986	1392
1987	1464
1988	3066
1989	1045
1990	14740
1991	19020
1992	20660
1993	21580
1994	26990
1995	25320
1996	27200
1997	28350
1998	29230
1999	31600
2000	30370
2001	36830
2002	40700
2003	41800
2004	43720
2005	41040
2006	40780
2007	40910