Year	Percent
1961-01-01	2.0768299999999997
1962-01-01	2.1310200000000000
1963-01-01	3.2630800000000000
1964-01-01	4.5234000000000000
1965-01-01	5.1442600000000000
1966-01-01	5.4202100000000000
1967-01-01	5.8985300000000000
1968-01-01	6.2733200000000000
1969-01-01	6.5825300000000000
1970-01-01	3.8563199999999997
1971-01-01	4.0348200000000000
1972-01-01	4.4847700000000000
1973-01-01	5.6840600000000000
1974-01-01	6.0749100000000000
1975-01-01	5.7778900000000000
1976-01-01	6.5681800000000000
1977-01-01	7.0223400000000000
1978-01-01	7.1407100000000000
1979-01-01	7.5929600000000010
1980-01-01	7.7607000000000000
1981-01-01	8.4199700000000000
1982-01-01	9.0508700000000000
1983-01-01	9.2558000000000000
1984-01-01	11.5245000000000000
1985-01-01	12.5305000000000000
1986-01-01	12.7631000000000000
1987-01-01	12.6972000000000000
1988-01-01	13.3625000000000000
1989-01-01	14.2251000000000000
1990-01-01	14.4069000000000000
1991-01-01	16.2394000000000000
1992-01-01	15.5817000000000000
1993-01-01	13.7714000000000000
1994-01-01	16.1184000000000000
1995-01-01	16.4180000000000000
1996-01-01	16.2567000000000000
1997-01-01	20.0994000000000000
1998-01-01	24.8863000000000000
1999-01-01	26.2895000000000000
2000-01-01	26.4408000000000000
2001-01-01	27.9721000000000000
2002-01-01	31.6422000000000000
2003-01-01	34.6439000000000000
2004-01-01	33.1796000000000000
2005-01-01	32.5475000000000000
2006-01-01	31.0446000000000000
2007-01-01	28.5673000000000000
2008-01-01	27.3936000000000000