Year	per person
1971	9.063
1972	9.589
1973	10.07
1974	10.14
1975	10.28
1976	10.53
1977	10.57
1978	10.37
1979	11.12
1980	11.12
1981	11.42
1982	10.84
1983	10.33
1984	10.55
1985	11.07
1986	12.41
1987	12.55
1988	13.81
1989	13.83
1990	17.75
1991	17.33
1992	20.79
1993	19.83
1994	20.49
1995	22.4
1996	30.85
1997	33.34
1998	33.66
1999	34.93
2000	36.06
2001	30.98
2002	32.38
2003	29.93
2004	32.25
2005	24.48
2006	23.26
2007	37.24
2008	38.63