Year	per person
1800	0.7597
1820	0.7757
1913	1.729
1950	3.388
1973	5.254
1990	4.372
1991	4.244
1992	3.69
1993	3.534
1994	3.288
1995	3.204
1996	3.206
1997	3.319
1998	3.41
1999	3.504
2000	3.586
2001	3.688
2002	3.781
2003	3.884
2004	4.115
2005	4.331
2006	4.586
2007	4.947
2008	5.316
2009	5.673