Year	per person
1971	10.1
1972	10.01
1973	9.911
1974	12.12
1975	16.78
1976	14.18
1977	19.15
1978	18.99
1979	18.83
1980	23.07
1981	24.08
1982	25.4
1983	24.35
1984	24.24
1985	25.01
1986	22.36
1987	24.15
1988	24.83
1989	26.48
1990	25.31
1991	20.4
1992	17.23
1993	15.99
1994	9.913
1995	16.18
1996	17.08
1997	11.72
1998	16.48
1999	17.86
2000	15.88
2001	15.56
2002	12.23
2003	11.97
2004	13.22
2005	13.18
2006	13.12
2007	10.12
2008	9.192