Year	per person
1800	1.281
1820	1.281
1913	0.8358
1950	0.7053
1951	0.7133
1952	0.7214
1953	0.7501
1954	0.7373
1955	0.7632
1956	0.7744
1957	0.7547
1958	0.7653
1959	0.7714
1960	0.7957
1961	0.8186
1962	0.8355
1963	0.9275
1964	0.9537
1965	0.9894
1966	1.007
1967	1.028
1968	1.024
1969	1.039
1970	1.075
1971	1.097
1972	1.128
1973	1.139
1974	1.127
1975	1.102
1976	1.104
1977	1.109
1978	1.079
1979	1.134
1980	1.172
1981	1.165
1982	1.151
1983	1.176
1984	1.127
1985	1.036
1986	1.078
1987	1.143
1988	1.124
1989	1.101
1990	1.045
1991	1.154
1992	1.278
1993	1.445
1994	1.743
1995	1.769
1996	1.899
1997	2.003
1998	1.985
1999	1.925
2000	1.626
2001	1.7
2002	1.678
2003	1.565
2004	1.523
2005	1.502
2006	1.395
2007	1.369
2008	1.197
2009	1.203