Year	Percent
1960-01-01	14.5540
1961-01-01	14.1296
1962-01-01	13.3457
1963-01-01	13.8698
1964-01-01	15.2565
1965-01-01	16.1214
1966-01-01	17.5471
1967-01-01	19.6439
1968-01-01	20.6083
1969-01-01	22.9041
1970-01-01	23.4121
1971-01-01	25.4409
1972-01-01	29.7566
1973-01-01	31.9238
1974-01-01	27.2756
1975-01-01	35.3077
1976-01-01	41.6902
1977-01-01	46.5567
1978-01-01	52.0129
1979-01-01	48.1945
1980-01-01	45.4558
1981-01-01	48.1462
1982-01-01	52.9043
1983-01-01	61.2778
1984-01-01	50.7238
1985-01-01	49.8044
1986-01-01	50.5083
1987-01-01	41.6648
1988-01-01	36.8982
1989-01-01	28.9528
1990-01-01	29.2066
1991-01-01	33.3228
1992-01-01	32.2699
1993-01-01	29.8495
1994-01-01	25.7663
1995-01-01	22.7568
1996-01-01	14.1229
1997-01-01	14.8833
1998-01-01	16.7482
1999-01-01	16.6573
2000-01-01	15.2420
2001-01-01	15.7341
2002-01-01	13.9407
2003-01-01	15.3145
2004-01-01	14.7841
2005-01-01	15.8975
2006-01-01	21.3241
2007-01-01	27.9646
2008-01-01	23.2662
2009-01-01	27.8727
2010-01-01	25.0119
2011-01-01	26.2382
2012-01-01	31.9890
2013-01-01	37.7504
2014-01-01	48.2940
2015-01-01	46.5258