Year	per person
1800	0.9227
1820	0.9227
1913	1.426
1950	3.072
1951	3.127
1952	3.181
1953	3.232
1954	3.284
1955	3.337
1956	3.387
1957	3.438
1958	3.488
1959	3.534
1960	3.526
1961	3.599
1962	3.629
1963	3.678
1964	3.659
1965	3.687
1966	3.681
1967	3.536
1968	3.658
1969	3.323
1970	3.503
1971	3.393
1972	3.504
1973	3.21
1974	3.245
1975	3.407
1976	3.63
1977	3.425
1978	3.189
1979	3.309
1980	3.101
1981	2.983
1982	3.33
1983	3.31
1984	3.061
1985	3.08
1986	3.132
1987	3.162
1988	3.224
1989	3.076
1990	3.121
1991	3.019
1992	3
1993	2.854
1994	2.857
1995	2.923
1996	2.988
1997	3.053
1998	3.142
1999	3.216
2000	3.315
2001	3.382
2002	3.333
2003	3.465
2004	3.576
2005	3.675
2006	3.677
2007	3.762
2008	3.76
2009	3.728