Year Percent 1960-01-01 31.49540000000000 1961-01-01 27.71020000000000 1962-01-01 33.06980000000000 1963-01-01 35.27110000000000 1964-01-01 34.14910000000000 1965-01-01 35.19540000000000 1966-01-01 49.49320000000000 1967-01-01 52.11020000000000 1968-01-01 52.58410000000000 1969-01-01 52.58410000000000 1970-01-01 52.58410000000000 1971-01-01 52.58410000000000 1972-01-01 52.58410000000000 1973-01-01 52.58410000000000 1974-01-01 52.58410000000000 1975-01-01 69.81580000000000 1976-01-01 58.70020000000000 1977-01-01 63.73850000000000 1978-01-01 62.59650000000000 1979-01-01 66.82810000000000 1980-01-01 74.13920000000000 1981-01-01 75.10800000000000 1982-01-01 75.03860000000000 1983-01-01 81.80980000000000 1984-01-01 87.84050000000000 1985-01-01 91.33600000000000 1986-01-01 87.00580000000000 1987-01-01 97.04060000000000 1988-01-01 106.27300000000000 1989-01-01 127.54000000000000 1990-01-01 122.12899999999999 1991-01-01 127.85500000000000 1992-01-01 111.93799999999999 1993-01-01 109.95800000000000 1994-01-01 101.91000000000000 1995-01-01 96.14650000000000 1996-01-01 97.16320000000000 1997-01-01 94.64160000000000 1998-01-01 93.17440000000000 1999-01-01 100.22300000000000 2000-01-01 107.58000000000000 2001-01-01 110.35600000000001 2002-01-01 112.20100000000001 2003-01-01 118.77799999999999 2004-01-01 120.25800000000000 2005-01-01 125.90600000000000 2006-01-01 123.43200000000000 2007-01-01 121.26500000000000 2008-01-01 117.30100000000000 2009-01-01 124.87799999999999 2010-01-01 131.44200000000000 2011-01-01 127.39100000000000 2012-01-01 119.26799999999999 2013-01-01 116.52300000000000 2014-01-01 121.44500000000000 2015-01-01 122.18799999999999 2016-01-01 120.94200000000001