Year Percent 1960-01-01 10.11940 1961-01-01 9.91173 1962-01-01 11.15760 1963-01-01 12.59420 1964-01-01 12.90280 1965-01-01 12.27040 1966-01-01 12.67580 1967-01-01 13.59540 1968-01-01 14.82680 1969-01-01 16.33500 1970-01-01 17.12650 1971-01-01 19.36420 1972-01-01 21.28570 1973-01-01 18.97120 1974-01-01 19.73780 1975-01-01 20.25850 1976-01-01 20.80420 1977-01-01 22.17490 1978-01-01 27.26590 1979-01-01 31.28760 1980-01-01 31.92600 1981-01-01 35.28140 1982-01-01 37.83250 1983-01-01 40.21110 1984-01-01 40.66190 1985-01-01 42.30890 1986-01-01 44.57940 1987-01-01 48.76410 1988-01-01 49.38290 1989-01-01 50.88030 1990-01-01 50.43960 1991-01-01 45.09840 1992-01-01 42.59930 1993-01-01 41.87970 1994-01-01 42.97960 1995-01-01 45.63340 1996-01-01 47.34220 1997-01-01 47.27590 1998-01-01 45.86330 1999-01-01 45.80120 2000-01-01 47.23870 2001-01-01 86.39930 2002-01-01 81.20530 2003-01-01 75.66390 2004-01-01 74.50680 2005-01-01 78.35690 2006-01-01 78.08970 2007-01-01 82.03600 2008-01-01 90.70210 2009-01-01 98.59760 2010-01-01 100.19900 2011-01-01 93.44770 2012-01-01 88.92420 2013-01-01 91.41970 2014-01-01 93.34560 2015-01-01 82.78780 2016-01-01 71.92830