Year	Index
1981-01-01	55.6
1987-01-01	53.4
1989-01-01	45.3
1992-01-01	42.5
1995-01-01	47.8
1998-01-01	49.8
1999-01-01	48.3
2001-01-01	48.2
2002-01-01	50.6
2003-01-01	50.4
2004-01-01	49.8
2005-01-01	52.4
2006-01-01	46.9