Year	per person
1800	1.183
1820	1.183
1950	1.499
1970	1.833
1971	1.816
1972	1.771
1973	1.731
1974	1.753
1975	1.634
1976	1.718
1977	1.79
1978	1.854
1979	1.882
1980	1.918
1981	2.08
1982	2.076
1983	2.192
1984	2.271
1985	2.335
1986	2.582
1987	3.277
1988	3.367
1989	3.543
1990	3.908
1991	3.958
1992	4.176
1993	4.362
1994	4.714
1995	5.081
1996	5.386
1997	5.617
1998	5.825
1999	6.119
2000	6.408
2001	6.68
2002	7.14
2003	7.47
2004	7.776
2005	8.101
2006	8.432
2007	9.913
2008	10.24
2009	11.08