Year	Percent
1960-01-01	1.92940
1961-01-01	70.22810
1962-01-01	69.00365
1963-01-01	67.70145
1964-01-01	66.03478
1965-01-01	67.20158
1966-01-01	67.77972
1967-01-01	68.15731
1968-01-01	69.17238
1969-01-01	70.22038
1970-01-01	69.09676
1980-01-01	48.83503
1981-01-01	51.72491
1982-01-01	52.65033
1983-01-01	58.29005
1984-01-01	64.48720
1985-01-01	67.13651
1986-01-01	62.48121
1987-01-01	59.85549
1988-01-01	64.14562
1989-01-01	70.70514
1990-01-01	68.28128
1991-01-01	69.79075
1992-01-01	78.56065
1993-01-01	86.45375
1994-01-01	89.41908
1995-01-01	88.14658
1996-01-01	94.94494
1997-01-01	108.96670
1998-01-01	117.63340
1999-01-01	135.83970
2000-01-01	142.72450
2001-01-01	141.07710
2002-01-01	134.41540
2003-01-01	125.53780
2004-01-01	117.35740
2005-01-01	114.64050
2006-01-01	112.43590