5,813
5,000
10,000
15,000
20,000
25,000
21,388
1988
17,129
1989
13,240
1990
10,681
1991
13,469
1992
14,656
1993
14,657
1994
28,357
1995
17,937
1996
13,051
1997
16,905
1998
17,142
1999
17,982
2000
17,977
2001
21,440
2002
25,243
2003
27,618
2004
18,748
2005
14,168
2006
11,595
2007
12,812
2008
7,403
2009
6,961
2010
6,389
2011
4,531
2012
5,813
2013
