Year	per person
1800	1.775
1820	1.775
1913	2.399
1938	8.353
1950	15.2
1965	32.13
1966	33.99
1967	31.24
1968	34.62
1969	32.52
1970	31.93
1971	34.6
1972	31.95
1973	33.38
1974	38.19
1975	35.22
1976	36.95
1977	36.58
1978	38.99
1979	39.32
1980	38.35
1981	40.4
1982	43.14
1983	44.2
1984	45.32
1985	46.53
1986	49.19
1987	51.44
1988	51.47
1989	51.85
1990	51.86
1991	53.28
1992	52.68
1993	51.7
1994	51.11
1995	50.4
1996	49.62
1997	49.64
1998	51.77
1999	52.9
2000	54.08
2001	53.89
2002	55.32
2003	56.2
2004	56.26
2005	57.05
2006	57.35
2007	57.85
2008	58.63