Year	per person
1800	1.518
1820	1.518
1913	2.346
1950	5.784
1951	5.943
1952	5.962
1953	6.01
1954	6.144
1955	6.08
1956	6.101
1957	6.073
1958	6.062
1959	6.23
1960	6.512
1961	6.653
1962	6.96
1963	7.253
1964	7.609
1965	8.152
1966	8.434
1967	8.818
1968	9.216
1969	9.861
1970	10.07
1971	10.1
1972	11.07
1973	10.97
1974	11.47
1975	11.11
1976	9.774
1977	9.473
1978	10.12
1979	10.51
1980	10.72
1981	10.87
1982	11.55
1983	11.99
1984	11.9
1985	11.83
1986	11.76
1987	11.63
1988	12.08
1989	12.19
1990	13.11
1991	13.65
1992	13.38
1993	13.11
1994	12.86
1995	12.61
1996	13.02
1997	13.32
1998	13.24
1999	13.29
2000	13.34
2001	13.4
2002	13.85
2003	14.32
2004	14.9
2005	15.52
2006	16.17
2007	16.82