1981	4.533
1982	4.613
1983	4.694
1984	4.774
1985	4.855
1986	4.938
1987	5.024
1988	5.110
1989	5.196
1990	5.284
1991	5.367
1992	5.450
1993	5.531
1994	5.611
1995	5.691
1996	5.769
1997	5.847
1998	5.925
1999	6.003
2000	6.080