Year	Years
1970	1.534
1971	2.051
1972	3.614
1973	5.139
1974	4.854
1975	5.461
1976	5.844
1977	6.871
1978	6.325
1979	5.757
1980	4.996
1981	4.282
1982	2.616
1983	2.154
1984	2.728
1985	2.475
1986	2.203
1987	2.021
1988	2.363
1989	3.058
1990	3.427
1991	4.174
1992	5.388
1993	5.162
1994	4.761
1995	5.256
1996	5.363
1997	5.058
1998	3.276
1999	2.559
2000	2.602
2001	2.051
2002	1.839
2003	1.743
2004	1.289