Year	Percent
1971-01-01	43.57570000000000
1972-01-01	40.32550000000000
1973-01-01	40.98620000000000
1974-01-01	39.52050000000000
1975-01-01	36.00370000000000
1976-01-01	31.92250000000000
1977-01-01	31.56150000000000
1978-01-01	30.64140000000000
1979-01-01	26.84170000000000
1980-01-01	29.89980000000000
1981-01-01	33.78670000000000
1982-01-01	31.09510000000000
1983-01-01	30.62200000000000
1984-01-01	30.93810000000000
1985-01-01	29.90350000000000
1986-01-01	32.09280000000000
1987-01-01	32.85260000000000
1988-01-01	35.04850000000000
1989-01-01	37.02160000000000
1990-01-01	37.48840000000000
1991-01-01	40.45500000000000
1992-01-01	43.02690000000000
1993-01-01	46.30670000000000
1994-01-01	55.74990000000000
1995-01-01	65.42770000000000
1996-01-01	72.02660000000000
1997-01-01	73.42930000000000
1998-01-01	75.47290000000000
1999-01-01	84.54880000000000
2000-01-01	88.31390000000000
2001-01-01	96.01799999999999
2002-01-01	101.06299999999999
2003-01-01	108.11399999999999
2004-01-01	98.21770000000000
2005-01-01	97.24070000000000
2006-01-01	89.17770000000000
2007-01-01	68.68450000000000
2008-01-01	56.01670000000000
2009-01-01	54.18330000000000
2010-01-01	58.35220000000000
2011-01-01	58.69150000000000
2012-01-01	52.23120000000000
2013-01-01	52.59120000000000
2014-01-01	61.86360000000000
2015-01-01	66.92110000000000
2016-01-01	67.69090000000000