Year	per person
1800	1.871
1820	1.871
1913	3.452
1970	10.62
1971	11.51
1972	12.36
1973	13.21
1974	14.13
1975	15.16
1976	16.33
1977	17.65
1978	19.06
1979	20.49
1980	21.88
1981	23.2
1982	24.45
1983	25.72
1984	27.14
1985	28.76
1986	30.61
1987	32.66
1988	34.91
1989	37.27
1990	39.28
1991	41.01
1992	42.42
1993	44.68
1994	47.69
1995	48.65
1996	51.01
1997	52.75
1998	56.37
1999	58.82
2000	58.82
2001	59.57
2002	56.79
2003	58.62
2004	62.15
2005	68.44
2006	77.56
2007	84.54
2008	94.67