Year Number 1950 77.614 1951 77.782 1952 77.573 1953 77.873 1954 78.752 1955 80.028 1956 80.483 1957 81.47 1958 82.764 1959 84.216 1960 85.766 1961 85.586 1962 85.781 1963 86.355 1964 87.096 1965 87.726 1966 86.801 1967 85.658 1968 84.598 1969 83.92 1970 83.62 1971 81.463 1972 80.51 1973 80.188 1974 79.713 1975 78.7 1976 77.652 1977 75.623 1978 73.194 1979 71.153 1980 69.805 1981 67.717 1982 66.713 1983 66.254 1984 65.599 1985 64.436 1986 63.749 1987 62.269 1988 60.452 1989 58.971 1990 58.105 1991 57.099 1992 56.873 1993 57.029 1994 56.93 1995 56.291 1996 56.183 1997 55.474 1998 54.45 1999 53.569 2000 53.039 2001 51.554 2002 50.32 2003 49.168 2004 47.948 2005 46.663 2006 46.037 2007 45.313 2008 44.33 2009 43.107 2010 41.816 2011 41.595 2012 41.255 2013 41.003 2014 40.994 2015 41.246 2016 41.691 2017 42.377 2018 43.22 2019 44.085 2020 44.896 2021 45.627 2022 46.333 2023 47.009 2024 47.68 2025 48.368 2026 49.098 2027 49.806 2028 50.479 2029 51.092 2030 51.628 2031 52.061 2032 52.411 2033 52.716 2034 53.029 2035 53.385 2036 53.753 2037 54.165 2038 54.589 2039 54.963 2040 55.258 2041 55.431 2042 55.535 2043 55.634 2044 55.827 2045 56.17 2046 56.621 2047 57.208 2048 57.896 2049 58.628 2050 59.367 2051 60.067 2052 60.762 2053 61.485 2054 62.267 2055 63.119 2056 63.959 2057 64.872 2058 65.802 2059 66.681 2060 67.476 2061 68.131 2062 68.717 2063 69.223 2064 69.618 2065 69.876 2066 69.89 2067 69.792 2068 69.628 2069 69.49 2070 69.461 2071 69.413 2072 69.465 2073 69.636 2074 69.912 2075 70.261 2076 70.513 2077 70.877 2078 71.314 2079 71.782 2080 72.274 2081 72.645 2082 73.044 2083 73.485 2084 73.974 2085 74.489 2086 74.851 2087 75.267 2088 75.718 2089 76.17 2090 76.62 2091 76.909 2092 77.22 2093 77.545 2094 77.88 2095 78.232 2096 78.406 2097 78.585 2098 78.779 2099 79.009 2100 79.285