Year	per person
1800	1.771
1820	1.808
1913	4.031
1950	7.898
1973	14.55
1990	17.81
1991	16.23
1992	14.58
1993	12.51
1994	9.691
1995	8.574
1996	7.782
1997	7.615
1998	7.535
1999	7.588
2000	8.115
2001	8.952
2002	9.506
2003	10.48
2004	11.84
2005	12.24
2006	13.22
2007	14.35
2008	14.73
2009	12.57