Year Number 1950 66.267 1951 67.393 1952 68.624 1953 69.406 1954 69.666 1955 69.565 1956 70.975 1957 71.668 1958 72.016 1959 72.299 1960 72.589 1961 73.562 1962 74.491 1963 75.276 1964 75.744 1965 75.862 1966 76.726 1967 77.242 1968 77.406 1969 77.134 1970 76.31 1971 81.126 1972 85.909 1973 90.651 1974 95.535 1975 100.738 1976 101.062 1977 100.774 1978 100.035 1979 99.236 1980 98.881 1981 88.005 1982 79.882 1983 73.918 1984 69.449 1985 66.036 1986 67.281 1987 68.521 1988 69.912 1989 71.617 1990 73.626 1991 76.586 1992 79.35 1993 81.899 1994 84.111 1995 85.873 1996 87.159 1997 88.068 1998 88.483 1999 88.274 2000 87.454 2001 86.704 2002 85.345 2003 83.626 2004 81.854 2005 80.188 2006 79.226 2007 78.289 2008 77.381 2009 76.456 2010 75.509 2011 75.024 2012 74.423 2013 73.805 2014 73.269 2015 72.851 2016 72.808 2017 72.782 2018 72.764 2019 72.723 2020 72.64 2021 72.778 2022 72.807 2023 72.742 2024 72.601 2025 72.392 2026 72.274 2027 72.045 2028 71.715 2029 71.289 2030 70.772 2031 70.301 2032 69.722 2033 69.049 2034 68.287 2035 67.449 2036 66.658 2037 65.783 2038 64.849 2039 63.874 2040 62.876 2041 61.946 2042 60.984 2043 60.028 2044 59.116 2045 58.271 2046 57.581 2047 56.923 2048 56.309 2049 55.752 2050 55.257 2051 54.916 2052 54.608 2053 54.327 2054 54.056 2055 53.785 2056 53.595 2057 53.395 2058 53.19 2059 52.983 2060 52.778 2061 52.63 2062 52.472 2063 52.313 2064 52.157 2065 52.01 2066 51.899 2067 51.79 2068 51.692 2069 51.615 2070 51.568 2071 51.565 2072 51.577 2073 51.611 2074 51.673 2075 51.765 2076 51.887 2077 52.026 2078 52.187 2079 52.371 2080 52.579 2081 52.804 2082 53.044 2083 53.299 2084 53.567 2085 53.849 2086 54.129 2087 54.416 2088 54.713 2089 55.019 2090 55.335 2091 55.629 2092 55.928 2093 56.236 2094 56.558 2095 56.895 2096 57.202 2097 57.521 2098 57.857 2099 58.211 2100 58.585