Year	Number
1981	2703
1982	3876
1983	3421
1984	2365
1985	2854
1988	5406
1989	7903
1992	9846
1993	9419
2000	13953
2001	12301
2002	11696
2003	12620
2004	13907
2005	15664
2006	14860
2007	16719
2008	20032
2009	18435
2010	22102