Year	Percent
1960-01-01	4.8853599999999995
1961-01-01	4.7472400000000010
1962-01-01	4.1541000000000000
1963-01-01	10.0808000000000000
1964-01-01	16.5080000000000000
1965-01-01	12.4032000000000000
1966-01-01	7.7730600000000010
1967-01-01	8.1406100000000000
1968-01-01	7.5911899999999990
1969-01-01	7.0265699999999995
1970-01-01	7.4897199999999990
1971-01-01	7.7219600000000000
1972-01-01	8.2246700000000000
1973-01-01	7.7926800000000010
1974-01-01	6.6336000000000000
1975-01-01	8.2431200000000000
1976-01-01	12.9393000000000000
1977-01-01	17.1614000000000000
1978-01-01	19.9682000000000000
1979-01-01	20.8575000000000000
1980-01-01	24.3924000000000000
1981-01-01	29.5825000000000000
1982-01-01	41.0049000000000000
1983-01-01	43.9010000000000000
1984-01-01	38.9817000000000000
1985-01-01	36.0271000000000000
1986-01-01	33.4632000000000000
1987-01-01	30.9773000000000000
1988-01-01	31.7332000000000000
1989-01-01	35.1124000000000000
1990-01-01	33.8829000000000000
1991-01-01	32.0994000000000000
1992-01-01	30.3190000000000030
1993-01-01	27.9548000000000000
1994-01-01	25.1868000000000000
1995-01-01	25.7852000000000000
1996-01-01	26.0937000000000000
1997-01-01	27.6176000000000000
1998-01-01	30.0550000000000000
1999-01-01	35.1080000000000040
2000-01-01	38.7595000000000000
2001-01-01	42.9345000000000000
2002-01-01	49.4602000000000000
2003-01-01	49.2578000000000000
2004-01-01	43.7793000000000000
2005-01-01	39.9158000000000000
2006-01-01	38.3237000000000000
2007-01-01	35.7393000000000000
2008-01-01	36.1157000000000000
2009-01-01	36.1111000000000000
2010-01-01	34.7176000000000000
2011-01-01	36.4727000000000000
2012-01-01	36.7432000000000000
2013-01-01	37.3583000000000000
2014-01-01	39.9274000000000000
2015-01-01	44.5979000000000000
2016-01-01	46.6647000000000000