Year	Percent
1960-01-01	19.9191000000000000
1961-01-01	20.4847000000000000
1962-01-01	22.7407000000000000
1963-01-01	23.1606000000000000
1964-01-01	22.4466000000000000
1965-01-01	23.0887000000000000
1966-01-01	23.2239000000000000
1967-01-01	24.9062000000000000
1968-01-01	26.2205000000000000
1969-01-01	27.5982000000000000
1970-01-01	24.6208000000000000
1971-01-01	26.2405000000000000
1972-01-01	26.1962000000000000
1973-01-01	24.3540000000000000
1974-01-01	22.0982000000000000
1975-01-01	21.8774000000000000
1976-01-01	23.0299000000000000
1977-01-01	18.6155000000000000
1978-01-01	14.2852000000000000
1979-01-01	14.8685000000000000
1980-01-01	14.7801000000000000
1981-01-01	14.9175000000000000
1982-01-01	12.4489000000000000
1983-01-01	9.8822300000000000
1984-01-01	9.7229800000000000
1985-01-01	9.6886900000000000
1986-01-01	9.4706300000000000
1987-01-01	7.7104800000000004
1988-01-01	8.7251500000000000
1989-01-01	11.0837000000000000
1990-01-01	13.6556000000000000
1991-01-01	16.0741000000000000
1992-01-01	21.3249000000000000
1993-01-01	23.9840000000000000
1994-01-01	27.5916000000000000
1995-01-01	26.5621000000000000
1996-01-01	17.5047000000000000
1997-01-01	16.8894000000000000
1998-01-01	18.2657000000000000
1999-01-01	16.1546000000000000
2000-01-01	14.2638000000000000
2001-01-01	12.9808000000000000
2002-01-01	12.3990000000000010
2003-01-01	13.2136000000000000
2004-01-01	12.5484000000000000
2005-01-01	12.9662000000000000
2006-01-01	14.4743000000000000
2007-01-01	16.5516000000000000
2008-01-01	16.8453000000000000
2009-01-01	17.6946000000000000
2010-01-01	17.4868000000000000
2011-01-01	18.0754000000000000
2012-01-01	19.1384000000000000
2013-01-01	20.7207000000000000
2014-01-01	21.2683000000000000
2015-01-01	22.1623000000000000
2016-01-01	23.8631000000000000