Year	per person
1800	1.358
1820	1.358
1913	0.9104
1950	0.7765
1951	0.7854
1952	0.7942
1953	0.8259
1954	0.8117
1955	0.8403
1956	0.8526
1957	0.8309
1958	0.8426
1959	0.8493
1960	0.876
1961	0.9012
1962	0.9199
1963	1.021
1964	1.05
1965	1.089
1966	1.109
1967	1.132
1968	1.127
1969	1.144
1970	1.184
1971	1.208
1972	1.242
1973	1.254
1974	1.24
1975	1.214
1976	1.216
1977	1.221
1978	1.188
1979	1.248
1980	1.29
1981	1.282
1982	1.267
1983	1.295
1984	1.241
1985	1.14
1986	1.187
1987	1.258
1988	1.238
1989	1.212
1990	1.151
1991	1.074
1992	0.924
1993	1.014
1994	1.009
1995	1.034
1996	1.125
1997	1.131
1998	1.056
1999	1.09
2000	1.124
2001	1.179
2002	1.162
2003	1.093
2004	1.205
2005	1.296
2006	1.408
2007	1.534
2008	1.662
2009	1.781