Year	per person
1971	4.09
1972	4.454
1973	6.618
1974	8.993
1975	9.406
1976	8.933
1977	9.063
1978	9.43
1979	9.302
1980	11.7
1981	11.57
1982	14.24
1983	13.01
1984	23.16
1985	24.18
1986	30.5
1987	29.04
1988	21.83
1989	20.94
1990	27.35
1991	24.23
1992	24.84
1993	24.31
1994	25.1
1995	25.52
1996	24.73
1997	20.65
1998	17.52
1999	28.11
2000	21.7
2001	29.3
2002	37.29
2003	37.47
2004	32.24
2005	38.3
2006	41.69
2007	45.03
2008	50.89