Year	Percent
1973-01-01	5.600560000000000
1974-01-01	5.724630000000000
1975-01-01	5.638960000000000
1976-01-01	5.249100000000000
1977-01-01	5.214590000000000
1978-01-01	6.364319999999999
1979-01-01	7.497669999999999
1980-01-01	7.549950000000000
1981-01-01	7.837720000000000
1982-01-01	8.388890000000000
1983-01-01	9.156160000000000
1984-01-01	10.989700000000000
1985-01-01	11.144500000000000
1986-01-01	11.304000000000000
1987-01-01	11.379800000000000
1988-01-01	11.959600000000000
1989-01-01	12.244700000000000
1990-01-01	12.945000000000000
1991-01-01	14.863600000000000
1992-01-01	13.432100000000000
1993-01-01	12.543600000000000
1994-01-01	14.530900000000000
1995-01-01	14.987000000000000
1996-01-01	17.066700000000000
1997-01-01	19.910500000000000
1998-01-01	22.721400000000000
1999-01-01	26.657500000000000
2000-01-01	27.823100000000000
2001-01-01	28.419800000000000
2002-01-01	31.132800000000000
2003-01-01	32.740700000000000
2004-01-01	27.721900000000000
2005-01-01	25.612300000000000
2006-01-01	27.504500000000000
2007-01-01	27.049100000000000
2008-01-01	25.144100000000000