Year	Percent
1960-01-01	10.21460000000000
1961-01-01	11.70390000000000
1962-01-01	14.14180000000000
1963-01-01	21.94110000000000
1964-01-01	29.97240000000000
1965-01-01	31.88250000000000
1966-01-01	31.62680000000000
1967-01-01	31.27810000000000
1968-01-01	33.27230000000000
1969-01-01	36.27450000000000
1970-01-01	37.57320000000000
1971-01-01	37.47890000000000
1972-01-01	37.23920000000000
1973-01-01	41.58470000000000
1974-01-01	49.98210000000000
1975-01-01	51.86790000000000
1976-01-01	47.28730000000000
1977-01-01	45.62860000000000
1978-01-01	47.13130000000000
1979-01-01	45.66610000000000
1980-01-01	39.82960000000000
1981-01-01	36.42520000000000
1982-01-01	31.78500000000000
1983-01-01	26.39240000000000
1984-01-01	20.55420000000000
1985-01-01	16.14270000000000
1986-01-01	20.39230000000000
1987-01-01	29.12040000000000
1988-01-01	32.93380000000000
1989-01-01	36.74760000000000
1990-01-01	39.82220000000000
1991-01-01	43.49720000000000
1992-01-01	49.13770000000000
1993-01-01	59.28790000000000
1994-01-01	68.57620000000000
1995-01-01	74.10180000000000
1996-01-01	81.51070000000000
1997-01-01	86.28820000000000
1998-01-01	89.00399999999999
1999-01-01	89.14760000000000
2000-01-01	87.79730000000000
2001-01-01	85.90020000000000
2002-01-01	83.60030000000000
2003-01-01	81.83740000000000
2004-01-01	80.82740000000000
2005-01-01	80.35020000000000
2006-01-01	82.48760000000000
2007-01-01	84.99720000000000
2008-01-01	83.36570000000000
2009-01-01	81.88570000000000
2010-01-01	82.87970000000000
2011-01-01	82.78540000000000
2012-01-01	81.17130000000000
2013-01-01	79.98050000000000
2014-01-01	79.53670000000000
2015-01-01	79.28530000000000
2016-01-01	78.52170000000000