Year	per person
1800	1.464
1820	1.464
1913	1.98
1973	4.111
1974	4.289
1975	4.435
1976	4.466
1977	4.641
1978	4.67
1979	4.711
1980	5.436
1981	6.221
1982	7.208
1983	7.727
1984	7.952
1985	8.533
1986	8.727
1987	8.966
1988	8.746
1989	8.718
1990	8.48
1991	8.963
1992	8.926
1993	9.2
1994	9.602
1995	9.847
1996	9.956
1997	9.721
1998	9.955
1999	10.35
2000	10.72
2001	11.02
2002	11.15
2003	11.47
2004	11.56
2005	11.26
2006	11.2
2007	11.22
2008	11.28
2009	11.19