Year Number 1950 77.18 1951 79.645 1952 82.755 1953 85.669 1954 87.861 1955 89.272 1956 91.515 1957 92.691 1958 93.268 1959 93.681 1960 94.044 1961 94.99 1962 96.025 1963 96.802 1964 96.898 1965 96.26 1966 97.154 1967 97.253 1968 96.799 1969 96.054 1970 94.98 1971 93.337 1972 91.418 1973 89.22 1974 86.852 1975 84.475 1976 81.542 1977 79.062 1978 76.83 1979 74.625 1980 72.412 1981 69.69 1982 67.243 1983 65.146 1984 63.547 1985 62.436 1986 61.107 1987 60.078 1988 59.225 1989 58.392 1990 57.538 1991 57.303 1992 56.889 1993 56.39 1994 55.949 1995 55.622 1996 55.361 1997 55.238 1998 55.132 1999 54.921 2000 54.567 2001 54.228 2002 53.787 2003 53.236 2004 52.598 2005 51.921 2006 51.887 2007 51.784 2008 51.631 2009 51.503 2010 51.454 2011 51.199 2012 51.119 2013 51.136 2014 51.174 2015 51.236 2016 51.331 2017 51.475 2018 51.651 2019 51.872 2020 52.166 2021 52.51 2022 52.901 2023 53.377 2024 53.985 2025 54.753 2026 55.608 2027 56.612 2028 57.737 2029 58.957 2030 60.25 2031 61.538 2032 62.899 2033 64.27 2034 65.565 2035 66.739 2036 67.644 2037 68.417 2038 69.071 2039 69.655 2040 70.205 2041 70.542 2042 70.847 2043 71.111 2044 71.321 2045 71.467 2046 71.356 2047 71.226 2048 71.091 2049 70.994 2050 70.986 2051 70.878 2052 70.878 2053 70.979 2054 71.161 2055 71.403 2056 71.499 2057 71.699 2058 71.987 2059 72.341 2060 72.753 2061 73.048 2062 73.443 2063 73.922 2064 74.51 2065 75.243 2066 75.921 2067 76.746 2068 77.7 2069 78.733 2070 79.796 2071 80.617 2072 81.482 2073 82.363 2074 83.248 2075 84.152 2076 84.779 2077 85.418 2078 86.09 2079 86.807 2080 87.561 2081 87.996 2082 88.505 2083 89.061 2084 89.647 2085 90.272 2086 90.592 2087 90.984 2088 91.441 2089 91.966 2090 92.567 2091 92.842 2092 93.207 2093 93.665 2094 94.203 2095 94.807 2096 95.032 2097 95.377 2098 95.816 2099 96.304 2100 96.821