Year Years 1800 445.4 1900 459.8 1930 431.1 1950 407.7 1951 402.9 1952 395.9 1953 388.3 1954 380.5 1955 372.2 1956 363.6 1957 354.7 1958 345.4 1959 336.4 1960 327.4 1961 318.7 1962 310 1963 301.5 1964 293.1 1965 283.8 1966 274.6 1967 264.8 1968 255.4 1969 246.5 1970 239.8 1971 236.7 1972 238.6 1973 244.8 1983 232.3 1984 222.4 1985 213.2 1986 204.3 1987 195.9 1988 187.8 1989 179.8 1990 172.1 1991 164.6 1992 157.5 1993 150.5 1994 143.8 1995 137.2 1996 130.7 1997 124.5 1998 118.4 1999 112.4 2000 106.6 2001 101 2002 95.5 2003 90.1 2004 85 2005 80.2 2006 75.5 2007 71.4 2008 67.7 2009 64.4 2010 61.6 2011 59 2012 56.8 2013 54.6