Year	per person
1800	1.897
1820	1.937
1913	4.318
1965	8.945
1966	9.015
1967	9.746
1968	10.08
1969	10.2
1970	12
1971	12.82
1972	13.37
1973	14.02
1974	14.59
1975	15.46
1976	16.12
1977	16.42
1978	16.75
1979	17.55
1980	18.15
1981	18.81
1982	19.14
1983	20.02
1984	21.05
1985	20.84
1986	21.7
1987	22.07
1988	23.05
1989	24.22
1990	22.41
1991	19.65
1992	13.49
1993	13.05
1994	13.53
1995	13.58
1996	14.23
1997	15.67
1998	16.68
1999	17.61
2000	18.97
2001	20.61
2002	22.14
2003	23.86
2004	26.07
2005	28.99
2006	32.7
2007	36.17
2008	34.68
2009	28.56