Year Number 1950 77.606 1951 79.71 1952 81.571 1953 83.426 1954 85.36 1955 87.378 1956 90.389 1957 93.273 1958 95.992 1959 98.422 1960 100.464 1961 102.889 1962 104.908 1963 106.491 1964 107.618 1965 108.313 1966 109.523 1967 110.163 1968 110.413 1969 110.502 1970 110.559 1971 111.183 1972 111.687 1973 112.068 1974 112.282 1975 112.313 1976 112.851 1977 113.058 1978 113.041 1979 112.924 1980 112.766 1981 112.942 1982 112.985 1983 112.863 1984 112.508 1985 111.889 1986 111.535 1987 110.842 1988 109.842 1989 108.54 1990 106.932 1991 105.399 1992 103.432 1993 101.194 1994 98.881 1995 96.597 1996 95.01 1997 93.571 1998 92.163 1999 90.659 2000 89.06 2001 88.053 2002 86.924 2003 85.794 2004 84.812 2005 84.034 2006 83.652 2007 83.33 2008 83.086 2009 82.894 2010 82.715 2011 82.471 2012 82.196 2013 81.863 2014 81.428 2015 80.869 2016 80.26 2017 79.535 2018 78.693 2019 77.748 2020 76.719 2021 75.783 2022 74.76 2023 73.68 2024 72.584 2025 71.502 2026 70.562 2027 69.627 2028 68.708 2029 67.81 2030 66.939 2031 66.213 2032 65.497 2033 64.804 2034 64.149 2035 63.54 2036 63.054 2037 62.588 2038 62.147 2039 61.733 2040 61.348 2041 61.05 2042 60.762 2043 60.486 2044 60.225 2045 59.98 2046 59.798 2047 59.612 2048 59.424 2049 59.237 2050 59.051 2051 58.897 2052 58.739 2053 58.565 2054 58.357 2055 58.109 2056 57.854 2057 57.56 2058 57.243 2059 56.925 2060 56.62 2061 56.342 2062 56.067 2063 55.807 2064 55.575 2065 55.383 2066 55.237 2067 55.118 2068 55.026 2069 54.958 2070 54.916 2071 54.908 2072 54.915 2073 54.933 2074 54.96 2075 54.992 2076 55.034 2077 55.072 2078 55.111 2079 55.151 2080 55.195 2081 55.23 2082 55.268 2083 55.309 2084 55.353 2085 55.403 2086 55.444 2087 55.486 2088 55.536 2089 55.604 2090 55.696 2091 55.775 2092 55.873 2093 55.99 2094 56.129 2095 56.291 2096 56.437 2097 56.602 2098 56.79 2099 56.998 2100 57.228