Year	Years
1980	8.848
1981	6.791
1982	7.067
1983	7.23
1984	6.077
1985	5.844
1986	5.774
1987	5.769
1988	5.646
1989	6.716
1990	6.914
1991	8.108
1992	6.857
1993	5.588
1994	5.722
1995	4.478
1996	4.536
1997	4.252
1998	4.017
1999	1.925
2000	3.009
2001	3.146
2002	2.618
2003	3.285
2004	4.365