Year	Years
1959	134.6
1960	129.2
1961	124
1962	118.9
1963	114.1
1964	109.7
1965	105.3
1966	101.2
1967	97.3
1968	93.6
1969	90.3
1970	87.3
1971	84.6
1972	82.2
1973	80.1
1974	78.4
1975	76.8
1976	75.5
1977	74.2
1978	72.8
1979	71.2
1980	69.5
1981	67.8
1982	65.8
1983	63.8
1984	61.8
1985	59.7
1986	57.8
1987	55.8
1988	53.7
1989	51.6
1990	49.6
1991	47.6
1992	45.9
1993	44.3
1994	43
1995	42.2
1996	41.8
1997	41.5
1998	41.5
1999	41.5
2000	41.5
2001	41.4
2002	41.2
2003	41
2004	40.7
2005	40.4
2006	40.1
2007	39.8
2008	39.5
2009	39.3
2010	39
2011	38.7
2012	38.2
2013	37.5