Year Number 1950 81.888 1951 82.706 1952 83.444 1953 84.05 1954 84.507 1955 84.844 1956 86.121 1957 87.052 1958 87.777 1959 88.412 1960 88.998 1961 90.072 1962 91.033 1963 91.811 1964 92.279 1965 92.387 1966 92.964 1967 93.046 1968 92.779 1969 92.332 1970 91.781 1971 91.58 1972 91.171 1973 90.59 1974 89.861 1975 89.015 1976 88.489 1977 87.883 1978 87.148 1979 86.197 1980 84.999 1981 84.187 1982 82.963 1983 81.525 1984 80.122 1985 78.868 1986 77.739 1987 76.826 1988 75.994 1989 75.045 1990 73.903 1991 73.092 1992 72.033 1993 70.839 1994 69.671 1995 68.595 1996 67.769 1997 66.993 1998 66.235 1999 65.441 2000 64.579 2001 63.612 2002 62.651 2003 61.666 2004 60.651 2005 59.634 2006 58.692 2007 57.722 2008 56.77 2009 55.909 2010 55.183 2011 54.611 2012 54.166 2013 53.815 2014 53.5 2015 53.188 2016 52.99 2017 52.754 2018 52.506 2019 52.284 2020 52.1 2021 51.875 2022 51.703 2023 51.559 2024 51.411 2025 51.25 2026 51.117 2027 50.967 2028 50.818 2029 50.703 2030 50.636 2031 50.603 2032 50.616 2033 50.67 2034 50.75 2035 50.852 2036 50.959 2037 51.084 2038 51.244 2039 51.458 2040 51.739 2041 52.041 2042 52.402 2043 52.811 2044 53.248 2045 53.7 2046 54.105 2047 54.524 2048 54.97 2049 55.463 2050 56.016 2051 56.546 2052 57.127 2053 57.751 2054 58.404 2055 59.074 2056 59.655 2057 60.259 2058 60.877 2059 61.492 2060 62.094 2061 62.565 2062 63.03 2063 63.498 2064 63.988 2065 64.515 2066 64.927 2067 65.38 2068 65.881 2069 66.428 2070 67.014 2071 67.466 2072 67.972 2073 68.531 2074 69.149 2075 69.836 2076 70.397 2077 71.031 2078 71.733 2079 72.48 2080 73.25 2081 73.827 2082 74.442 2083 75.089 2084 75.76 2085 76.456 2086 76.948 2087 77.479 2088 78.045 2089 78.639 2090 79.263 2091 79.655 2092 80.085 2093 80.558 2094 81.079 2095 81.645 2096 81.957 2097 82.332 2098 82.77 2099 83.258 2100 83.788