Year	Percent
1973-01-01	44.2617
1974-01-01	44.3830
1975-01-01	45.9828
1976-01-01	46.8169
1977-01-01	50.3653
1978-01-01	54.0807
1979-01-01	56.4595
1980-01-01	58.0428
1981-01-01	64.7877
1982-01-01	73.3436
1983-01-01	68.7814
1984-01-01	65.9243
1985-01-01	65.8493
1986-01-01	67.0690
1987-01-01	66.1546
1988-01-01	67.4887
1989-01-01	71.5079
1990-01-01	76.1505
1991-01-01	82.3149
1992-01-01	84.3638
1993-01-01	85.7430
1994-01-01	84.6944
1995-01-01	85.7034
1996-01-01	87.6885
1997-01-01	89.5063
1998-01-01	89.9133
1999-01-01	85.8025
2000-01-01	81.5722
2001-01-01	107.7270
2002-01-01	129.5990
2003-01-01	124.7650
2004-01-01	122.1020
2005-01-01	126.1410
2006-01-01	136.8090
2007-01-01	137.4170
2008-01-01	136.3920