Year	Percent
1960-01-01	11.7276
1961-01-01	11.1882
1962-01-01	11.1297
1963-01-01	10.5159
1964-01-01	10.1440
1965-01-01	10.6899
1966-01-01	11.0235
1967-01-01	10.9225
1968-01-01	11.5971
1969-01-01	11.9200
1970-01-01	11.5238
1971-01-01	12.6926
1972-01-01	14.1663
1973-01-01	13.9789
1974-01-01	13.7213
1975-01-01	14.3639
1976-01-01	17.3406
1977-01-01	20.2051
1978-01-01	22.2302
1979-01-01	24.5106
1980-01-01	23.4261
1981-01-01	24.0436
1982-01-01	25.0615
1983-01-01	25.7035
1984-01-01	26.8491
1985-01-01	27.9415
1986-01-01	29.9452
1987-01-01	30.8774
1988-01-01	30.7764
1989-01-01	30.7612
1990-01-01	30.4592
1991-01-01	31.0476
1992-01-01	32.5169
1993-01-01	32.5323
1994-01-01	32.9878
1995-01-01	32.1402
1996-01-01	31.4755
1997-01-01	33.7861
1998-01-01	35.9874
1999-01-01	37.0290
2000-01-01	41.1279
2001-01-01	43.8170
2002-01-01	47.3838
2003-01-01	48.7297
2004-01-01	49.1329
2005-01-01	50.0016
2006-01-01	51.2346
2007-01-01	54.4358
2008-01-01	59.2280
2009-01-01	60.7045
2010-01-01	59.5859
2011-01-01	62.8341
2012-01-01	63.0713
2013-01-01	63.3195
2014-01-01	64.2646
2015-01-01	64.4961
2016-01-01	65.9640