Year	Percent
1960-01-01	4.3989100000000000
1961-01-01	4.1753900000000000
1962-01-01	5.0849699999999990
1963-01-01	5.5143500000000000
1964-01-01	5.3489100000000000
1965-01-01	4.9919300000000000
1966-01-01	5.3061099999999990
1967-01-01	5.5980099999999995
1968-01-01	6.0497100000000000
1969-01-01	6.8529899999999990
1970-01-01	2.2032200000000000
1971-01-01	2.7124000000000000
1972-01-01	2.8901500000000000
1973-01-01	2.8691500000000000
1974-01-01	3.4465199999999996
1975-01-01	8.8021700000000000
1976-01-01	9.7201700000000000
1977-01-01	8.5628100000000000
1978-01-01	9.2721900000000000
1979-01-01	8.1832200000000000
1980-01-01	8.8467500000000000
1981-01-01	13.2822000000000000
1982-01-01	14.7622000000000000
1983-01-01	16.6327000000000000
1984-01-01	16.3556000000000000
1985-01-01	16.9164000000000000
1986-01-01	17.1195000000000000
1987-01-01	15.4314000000000000
1988-01-01	13.8049000000000000
1989-01-01	12.5645000000000000
1990-01-01	13.8414000000000000
1991-01-01	17.6694000000000000
1992-01-01	18.9728000000000000
1993-01-01	20.6172000000000000
1994-01-01	19.7848000000000000
1995-01-01	16.9717000000000000
1996-01-01	16.5235000000000000
1997-01-01	15.3782000000000000
1998-01-01	14.3593000000000000
1999-01-01	12.6867000000000000
2000-01-01	13.0593000000000000
2001-01-01	14.2055000000000000
2002-01-01	14.6862000000000000
2003-01-01	14.9847000000000000
2004-01-01	14.9469000000000000
2005-01-01	15.4687000000000000
2006-01-01	16.3265000000000000
2007-01-01	18.7297000000000000
2008-01-01	21.4229000000000000
2009-01-01	23.2476000000000000
2010-01-01	25.3377000000000000
2011-01-01	25.7229000000000000
2012-01-01	25.0771000000000000
2013-01-01	25.1262000000000000
2014-01-01	27.1996000000000000
2015-01-01	30.0559000000000000
2016-01-01	30.6903000000000000