Year Percent 1960-01-01 54.43645 1961-01-01 56.97538 1962-01-01 60.96386 1963-01-01 65.35519 1964-01-01 72.83176 1965-01-01 72.81554 1966-01-01 70.65421 1967-01-01 67.49792 1968-01-01 67.81609 1969-01-01 70.12696 1970-01-01 73.75256 1971-01-01 75.49313 1972-01-01 88.68097 1973-01-01 91.69274 1974-01-01 95.98021 1975-01-01 90.46783 1976-01-01 93.16148 1977-01-01 94.97827 1978-01-01 94.61911 1979-01-01 99.98134 1980-01-01 98.72966 1981-01-01 97.93608 1982-01-01 105.46330 1983-01-01 112.63290 1984-01-01 120.46030 1985-01-01 123.36210 1986-01-01 189.62130 1987-01-01 116.59250 1988-01-01 123.64630 1989-01-01 127.49200 1990-01-01 127.16990 1991-01-01 128.54820 1992-01-01 188.91840 1993-01-01 186.76280 1994-01-01 182.78410 1995-01-01 168.06320 1996-01-01 160.79880 1997-01-01 135.89190 1998-01-01 132.94760 1999-01-01 119.95310 2000-01-01 123.72240 2001-01-01 124.15020 2002-01-01 127.85010 2003-01-01 127.79360 2004-01-01 129.15580 2005-01-01 125.07180 2006-01-01 123.93290 2007-01-01 124.58880 2008-01-01 125.24160 2009-01-01 125.85190