Year	Years
1990	73.6
1991	73.7
1992	73.8
1993	74
1994	74.2
1995	74.7
1996	75
1997	75.2
1998	75.4
1999	75.6
2000	75.8
2001	76
2002	76.2
2003	76.5
2004	76.8
2005	77.2
2006	77.6
2007	78
2008	78.5
2009	79
2010	79.5
2011	79.8
2012	79.9
2013	80