Year Number 1950 50.386 1951 51.148 1952 51.762 1953 52.352 1954 52.859 1955 53.166 1956 53.061 1957 52.957 1958 52.744 1959 52.39 1960 51.938 1961 51.76 1962 51.387 1963 50.961 1964 50.667 1965 50.596 1966 50.83 1967 51.18 1968 51.652 1969 52.176 1970 52.686 1971 53.415 1972 54.124 1973 54.778 1974 55.336 1975 55.774 1976 56.077 1977 56.225 1978 56.241 1979 56.151 1980 55.969 1981 55.749 1982 55.48 1983 55.192 1984 54.944 1985 54.799 1986 54.814 1987 54.924 1988 55.113 1989 55.337 1990 55.562 1991 56.019 1992 56.404 1993 56.731 1994 56.958 1995 57.023 1996 57.07 1997 56.843 1998 56.42 1999 55.944 2000 55.51 2001 54.69 2002 54.173 2003 53.829 2004 53.488 2005 53.108 2006 53.165 2007 52.998 2008 52.773 2009 52.775 2010 53.164 2011 53.85 2012 54.967 2013 56.437 2014 57.967 2015 59.304 2016 60.397 2017 61.306 2018 62.022 2019 62.609 2020 63.134 2021 63.721 2022 64.202 2023 64.599 2024 64.949 2025 65.274 2026 65.527 2027 65.743 2028 65.964 2029 66.249 2030 66.635 2031 67.019 2032 67.528 2033 68.079 2034 68.553 2035 68.883 2036 69.016 2037 69.035 2038 68.992 2039 68.942 2040 68.905 2041 68.86 2042 68.866 2043 68.899 2044 68.946 2045 69.032 2046 69.132 2047 69.276 2048 69.49 2049 69.784 2050 70.145 2051 70.421 2052 70.763 2053 71.165 2054 71.64 2055 72.207 2056 72.734 2057 73.369 2058 74.023 2059 74.529 2060 74.764 2061 74.598 2062 74.234 2063 73.733 2064 73.219 2065 72.802 2066 72.359 2067 72.016 2068 71.793 2069 71.695 2070 71.718 2071 71.677 2072 71.782 2073 72.003 2074 72.299 2075 72.641 2076 72.822 2077 73.06 2078 73.356 2079 73.717 2080 74.143 2081 74.394 2082 74.711 2083 75.104 2084 75.552 2085 76.021 2086 76.3 2087 76.661 2088 77.028 2089 77.37 2090 77.721 2091 77.882 2092 78.018 2093 78.189 2094 78.442 2095 78.765 2096 78.78 2097 78.889 2098 79.074 2099 79.298 2100 79.544