Year	Years
1980	5.805
1981	5.716
1982	5.788
1983	5.908
1984	6.432
1985	5.552
1986	6.135
1987	7.403
1988	7.239
1989	5.834
1990	3.795
1991	3.829
1992	3.568
1993	2.916
1994	2.589
1995	3.723
1996	3.261
1997	2.953
1998	3.528
1999	3.277
2000	3.516
2001	3.344
2002	3.63
2003	4.546