Year	per person
1800	1.183
1820	1.183
1913	1.6
1973	12.99
1974	14.31
1975	13.73
1976	13.28
1977	13.15
1978	13.43
1979	13.24
1980	11.82
1981	12.07
1982	11.9
1983	13.22
1984	12.96
1985	12.04
1986	14.05
1987	15.17
1988	15.88
1989	15.4
1990	16.36
1991	16.7
1992	16.64
1993	16.2
1994	15.76
1995	15.6
1996	13.6
1997	12.88
1998	12.39
1999	11.98
2000	12.5
2001	12.69
2002	12.98
2003	13.19
2004	13.66
2005	13.61
2006	13.49
2007	13.64
2008	13.53