Year	per person
1800	1.063
1820	1.063
1913	1.642
1950	3.403
1951	3.47
1952	3.544
1953	3.611
1954	3.684
1955	3.76
1956	4.045
1957	3.882
1958	3.933
1959	4.282
1960	4.244
1961	4.129
1962	4.297
1963	4.062
1964	3.915
1965	4.081
1966	3.925
1967	3.702
1968	3.825
1969	3.954
1970	3.682
1971	3.827
1972	3.64
1973	3.232
1974	3.452
1975	3.773
1976	4.329
1977	4.831
1978	4.593
1979	3.965
1980	3.862
1981	3.815
1982	4.157
1983	3.973
1984	3.641
1985	3.28
1986	3.309
1987	3.307
1988	3.277
1989	3.453
1990	3.082
1991	3.199
1992	3.272
1993	3.278
1994	3.253
1995	3.264
1996	3.343
1997	3.579
1998	3.686
1999	3.856
2000	4.11
2001	4.239
2002	4.371
2003	4.556
2004	4.662
2005	4.932
2006	5.35
2007	5.744
2008	5.981
2009	6.093