Year	per person
1800	0.8092
1820	0.8092
1913	0.9626
1950	1.031
1951	1.07
1952	1.082
1953	1.101
1954	1.139
1955	1.151
1956	1.168
1957	1.185
1958	1.191
1959	1.23
1960	1.237
1961	1.179
1962	1.31
1963	1.152
1964	0.9909
1965	1.034
1966	1.076
1967	1.121
1968	1.166
1969	1.256
1970	1.352
1971	1.329
1972	1.295
1973	1.297
1974	1.32
1975	1.519
1976	1.445
1977	1.469
1978	1.559
1979	1.652
1980	1.795
1981	1.85
1982	1.933
1983	1.979
1984	1.844
1985	1.877
1986	1.93
1987	1.86
1988	1.74
1989	1.724
1990	1.668
1991	1.555
1992	1.616
1993	1.449
1994	0.8387
1995	1.275
1996	1.366
1997	1.294
1998	1.412
1999	1.486
2000	1.544
2001	1.612
2002	1.723
2003	1.698
2004	1.723
2005	1.783
2006	1.901
2007	1.965
2008	2.14
2009	2.183