Year	per person
1800	1.331
1820	1.331
1913	1.8
1950	4.759
1970	18.54
1971	19.39
1972	20.49
1973	21.8
1974	23.27
1975	24.87
1976	26.55
1977	28.38
1978	30.28
1979	31.83
1980	33.37
1981	34.73
1982	34.77
1983	36.67
1984	38.08
1985	36.66
1986	37.41
1987	41.01
1988	42.44
1989	42.98
1990	44.95
1991	45.37
1992	50.26
1993	51.87
1994	53.17
1995	54.06
1996	53.04
1997	52.17
1998	49.13
1999	47.34
2000	49.37
2001	50.06
2002	54.29
2003	61.06
2004	77.33
2005	81.7
2006	93.25
2007	114.1
2008	126