Year	per person
1800	1.253
1820	1.279
1913	2.851
1965	5.946
1966	6.32
1967	6.644
1968	6.874
1969	7.136
1970	7.925
1971	8.048
1972	8.204
1973	8.662
1974	9.35
1975	9.965
1976	10.5
1977	11.15
1978	11.91
1979	12.7
1980	13.19
1981	13.78
1982	13.95
1983	14.43
1984	15.08
1985	15.68
1986	14.25
1987	14.29
1988	14.95
1989	13.81
1990	11.79
1991	9.382
1992	5.248
1993	3.782
1994	3.458
1995	3.614
1996	4.082
1997	4.574
1998	4.772
1999	4.965
2000	5.115
2001	5.423
2002	5.784
2003	6.494
2004	6.946
2005	7.686
2006	8.255
2007	9.288
2008	9.53
2009	9.142