Year	Percent
1974-01-01	5.3472800000000005
1975-01-01	5.2152100000000000
1976-01-01	4.8496800000000000
1977-01-01	10.5836000000000000
1978-01-01	16.3508000000000000
1979-01-01	16.0223000000000000
1980-01-01	15.8578000000000000
1981-01-01	15.3418000000000000
1982-01-01	15.4084000000000000
1983-01-01	14.9463000000000000
1984-01-01	15.0879000000000000
1985-01-01	15.7645000000000000
1986-01-01	16.8215000000000000
1987-01-01	17.0051000000000000
1988-01-01	16.9017000000000000
1989-01-01	17.4831000000000000
1990-01-01	18.5210000000000000
1991-01-01	19.9712000000000000
1992-01-01	20.7301000000000000
1993-01-01	21.2776000000000000
1994-01-01	20.9282000000000000
1995-01-01	21.3134000000000000
1996-01-01	21.7325000000000000
1997-01-01	22.1018000000000000
1998-01-01	22.9682000000000000
1999-01-01	23.7279000000000000
2000-01-01	23.9779000000000000
2001-01-01	43.1334000000000000
2002-01-01	59.8856000000000000
2003-01-01	57.9505000000000000
2004-01-01	57.3514000000000000
2005-01-01	58.5063000000000000
2006-01-01	61.3328000000000000