Year	per person
1800	3.05
1820	3.114
1870	4.562
1890	6.154
1900	7.031
1910	8.36
1913	8.768
1920	7.142
1924	7.991
1925	9.525
1926	9.036
1927	9.35
1928	10.09
1929	10.35
1930	10.05
1931	9.48
1932	9.162
1933	9.921
1934	9.903
1935	10.33
1936	10.94
1937	10.63
1938	11.1
1939	11.86
1940	10.98
1941	10.98
1942	11.46
1946	7.192
1947	7.412
1948	9.195
1949	9.839
1950	10.36
1951	11.26
1952	11.54
1953	11.64
1954	11.91
1955	12.83
1956	12.14
1957	13.25
1958	14.07
1959	14.56
1960	15.25
1961	15.95
1962	16.56
1963	17.42
1964	18.34
1965	18.43
1966	19.42
1967	20.45
1968	20.62
1969	21.16
1970	21.01
1971	21.89
1972	22.3
1973	23.39
1974	23.89
1975	24.26
1976	24.2
1977	25.6
1978	26.13
1979	26.12
1980	26.36
1981	26.54
1982	27.51
1983	27.27
1984	28.04
1985	27.4
1986	28
1987	28.48
1988	29.38
1989	28.85
1990	26.99
1991	23.8
1992	23.1
1993	23.02
1994	23.73
1995	24.12
1996	24.5
1997	25.69
1998	27.02
1999	28.23
2000	29.81
2001	31.11
2002	32.55
2003	34
2004	35.73
2005	37.31
2006	38.87
2007	39.29
2008	39.62
2009	37.24