Year	per person
1800	1.13
1820	1.169
1950	3.346
1960	5.045
1961	5.102
1962	4.936
1963	4.946
1964	5.047
1965	5.377
1966	5.93
1967	6.313
1968	6.927
1969	7.347
1970	8.257
1971	8.522
1972	9.056
1973	9.937
1974	10.86
1975	12.84
1976	14.75
1977	16.12
1978	17.41
1979	18.83
1980	19.97
1981	20.62
1982	21.24
1983	21.39
1984	21.97
1985	22.98
1986	23.63
1987	24.35
1988	26.18
1989	28.08
1990	29.59
1991	31.18
1992	32.34
1993	33.46
1994	35.03
1995	36.8
1996	38.06
1997	39.58
1998	40.75
1999	42.05
2000	44.47
2001	43.42
2002	44.22
2003	43.79
2004	43.58
2005	44.76
2006	46.06
2007	47.52
2008	48.1
2009	46.77