Year	per person
1800	1.572
1820	1.606
1913	3.579
1950	7.013
1973	10.87
1990	14.93
1991	14.68
1992	13.19
1993	12.12
1994	10.68
1995	9.552
1996	9.814
1997	10.94
1998	11.87
1999	12.29
2000	13.02
2001	13.65
2002	14.35
2003	15.35
2004	17.12
2005	18.73
2006	20.68
2007	22.53
2008	24.83
2009	25.38