Year	per person
1800	1.935
1820	1.945
1913	3.336
1950	3.688
1951	3.844
1952	4.009
1953	4.182
1954	4.355
1955	4.535
1956	4.728
1957	4.918
1958	5.127
1959	5.328
1960	5.532
1961	5.464
1962	6.414
1963	6.526
1964	6.365
1965	6.234
1966	6.39
1967	10.35
1968	18.31
1969	22.39
1970	22.48
1971	21.99
1972	23.29
1973	19.41
1974	20.96
1975	25.25
1976	27.21
1977	25.98
1978	24.18
1979	23.93
1980	24.1
1981	26.77
1982	28.41
1983	31.64
1984	35.37
1985	38.74
1986	38.13
1987	39.73
1988	39.48
1989	39.7
1990	38.35
1991	39.1
1992	40.83
1993	41.71
1994	41.85
1995	42.38
1996	42.12
1997	43.21
1998	42.86
1999	41.32
2000	42.11
2001	43.74
2002	43.37
2003	42.76
2004	43.58
2005	44.59
2006	46.02
2007	46.58
2008	49.98
2009	50.01