Year	per person
1800	1.7
1820	1.7
1913	2.775
1950	6.189
1951	6.366
1952	6.759
1953	7.132
1954	7.392
1955	7.648
1956	8.199
1957	8.568
1958	8.665
1959	9.35
1960	9.875
1961	10.62
1962	11.2
1963	12.13
1964	12.7
1965	13.62
1966	14.41
1967	15.2
1968	15.77
1969	16.86
1970	18.33
1971	19.18
1972	20.01
1973	21.08
1974	20.92
1975	20.05
1976	20.48
1977	21.43
1978	22.57
1979	23.57
1980	23.62
1981	23.66
1982	22.66
1983	22.51
1984	23.91
1985	24.17
1986	25.9
1987	26.93
1988	28.43
1989	29.58
1990	30.42
1991	30.91
1992	32.11
1993	33.32
1994	34.39
1995	35.63
1996	36.39
1997	37.28
1998	38.25
1999	39.66
2000	40.72
2001	41.36
2002	41.35
2003	41.81
2004	42.3
2005	43.26
2006	42.47
2007	41.7
2008	41.6