Year Number 1950 73.703 1951 74.722 1952 76.499 1953 78.071 1954 79.063 1955 79.562 1956 81.543 1957 82.508 1958 83.028 1959 83.613 1960 84.423 1961 85.597 1962 87.028 1963 88.379 1964 89.136 1965 89.095 1966 89.243 1967 88.651 1968 87.576 1969 86.407 1970 85.36 1971 84.81 1972 84.328 1973 83.891 1974 83.452 1975 83.001 1976 82.895 1977 82.641 1978 82.252 1979 81.719 1980 81.033 1981 80.145 1982 79.086 1983 77.898 1984 76.611 1985 75.244 1986 74.19 1987 72.988 1988 71.675 1989 70.305 1990 68.912 1991 67.578 1992 66.248 1993 64.934 1994 63.664 1995 62.47 1996 61.465 1997 60.558 1998 59.713 1999 58.874 2000 58.012 2001 57.327 2002 56.535 2003 55.71 2004 54.939 2005 54.249 2006 53.538 2007 52.922 2008 52.361 2009 51.819 2010 51.31 2011 50.92 2012 50.57 2013 50.269 2014 50 2015 49.721 2016 49.467 2017 49.143 2018 48.79 2019 48.489 2020 48.294 2021 48.042 2022 47.96 2023 47.995 2024 48.048 2025 48.073 2026 48.122 2027 48.149 2028 48.173 2029 48.244 2030 48.387 2031 48.528 2032 48.714 2033 48.959 2034 49.268 2035 49.645 2036 50.032 2037 50.483 2038 50.995 2039 51.564 2040 52.189 2041 52.796 2042 53.447 2043 54.143 2044 54.884 2045 55.664 2046 56.379 2047 57.13 2048 57.903 2049 58.681 2050 59.453 2051 60.108 2052 60.762 2053 61.414 2054 62.065 2055 62.716 2056 63.229 2057 63.744 2058 64.279 2059 64.858 2060 65.498 2061 66.034 2062 66.64 2063 67.303 2064 67.996 2065 68.697 2066 69.233 2067 69.797 2068 70.388 2069 71.003 2070 71.637 2071 72.103 2072 72.607 2073 73.155 2074 73.751 2075 74.393 2076 74.886 2077 75.457 2078 76.084 2079 76.731 2080 77.376 2081 77.81 2082 78.27 2083 78.754 2084 79.258 2085 79.784 2086 80.072 2087 80.402 2088 80.778 2089 81.193 2090 81.635 2091 81.823 2092 82.078 2093 82.386 2094 82.734 2095 83.115 2096 83.258 2097 83.465 2098 83.733 2099 84.058 2100 84.433