Year Number 1950 81.567 1951 82.768 1952 84.466 1953 85.922 1954 86.923 1955 87.603 1956 89.545 1957 90.646 1958 91.406 1959 92.249 1960 93.303 1961 94.205 1962 95.481 1963 96.753 1964 97.439 1965 97.264 1966 97.327 1967 96.579 1968 95.28 1969 93.912 1970 92.758 1971 91.845 1972 91.251 1973 90.749 1974 89.741 1975 87.767 1976 86.353 1977 83.877 1978 80.875 1979 78.567 1980 77.914 1981 76.432 1982 77.321 1983 79.592 1984 81.609 1985 82.593 1986 85.772 1987 86.649 1988 86.524 1989 87.185 1990 89.32 1991 90.708 1992 93.393 1993 96.42 1994 98.222 1995 98.049 1996 97.312 1997 94.561 1998 90.23 1999 85.378 2000 80.757 2001 76.989 2002 74.087 2003 71.872 2004 69.925 2005 67.938 2006 65.841 2007 63.822 2008 61.892 2009 60.209 2010 58.88 2011 58.017 2012 57.113 2013 56.331 2014 55.809 2015 55.57 2016 55.409 2017 55.545 2018 55.816 2019 55.98 2020 55.913 2021 55.738 2022 55.339 2023 54.798 2024 54.264 2025 53.814 2026 53.374 2027 53.021 2028 52.705 2029 52.356 2030 51.951 2031 51.563 2032 51.129 2033 50.692 2034 50.316 2035 50.032 2036 49.863 2037 49.811 2038 49.778 2039 49.606 2040 49.225 2041 48.66 2042 47.869 2043 47.115 2044 46.755 2045 46.972 2046 47.68 2047 48.935 2048 50.461 2049 51.823 2050 52.76 2051 53.287 2052 53.423 2053 53.353 2054 53.37 2055 53.638 2056 54.053 2057 54.666 2058 55.397 2059 56.116 2060 56.746 2061 57.253 2062 57.704 2063 58.112 2064 58.485 2065 58.82 2066 59.014 2067 59.182 2068 59.328 2069 59.51 2070 59.794 2071 60.069 2072 60.389 2073 60.83 2074 61.363 2075 61.918 2076 62.393 2077 62.922 2078 63.511 2079 64.075 2080 64.65 2081 65.21 2082 65.761 2083 66.354 2084 67.006 2085 67.669 2086 68.14 2087 68.655 2088 69.179 2089 69.686 2090 70.187 2091 70.559 2092 70.948 2093 71.368 2094 71.834 2095 72.348 2096 72.714 2097 73.131 2098 73.591 2099 74.105 2100 74.689