Year Number 1950 50.62 1951 51.437 1952 51.817 1953 51.993 1954 52.026 1955 51.816 1956 52.425 1957 52.649 1958 52.809 1959 53.011 1960 53.104 1961 53.438 1962 53.347 1963 53.355 1964 53.675 1965 54.176 1966 54.242 1967 54.078 1968 54.186 1969 54.654 1970 55.242 1971 55.289 1972 54.986 1973 54.433 1974 53.699 1975 52.833 1976 52.568 1977 52.138 1978 51.539 1979 50.775 1980 49.899 1981 49.04 1982 48.061 1983 47.109 1984 46.29 1985 45.637 1986 45.273 1987 44.948 1988 44.722 1989 44.542 1990 44.343 1991 44.738 1992 45.015 1993 45.252 1994 45.523 1995 45.8 1996 45.937 1997 46.065 1998 46.156 1999 46.139 2000 45.992 2001 45.943 2002 45.805 2003 45.596 2004 45.372 2005 45.216 2006 45.418 2007 45.496 2008 45.44 2009 45.301 2010 45.181 2011 45.424 2012 45.717 2013 46.081 2014 46.516 2015 47.009 2016 47.571 2017 48.206 2018 48.892 2019 49.596 2020 50.307 2021 51.077 2022 51.831 2023 52.608 2024 53.459 2025 54.409 2026 55.449 2027 56.567 2028 57.739 2029 58.93 2030 60.117 2031 61.26 2032 62.384 2033 63.473 2034 64.518 2035 65.5 2036 66.338 2037 67.097 2038 67.788 2039 68.444 2040 69.089 2041 69.617 2042 70.116 2043 70.602 2044 71.081 2045 71.555 2046 71.918 2047 72.286 2048 72.645 2049 72.977 2050 73.281 2051 73.473 2052 73.633 2053 73.787 2054 73.98 2055 74.216 2056 74.408 2057 74.66 2058 74.95 2059 75.228 2060 75.483 2061 75.635 2062 75.783 2063 75.931 2064 76.083 2065 76.247 2066 76.316 2067 76.395 2068 76.503 2069 76.65 2070 76.831 2071 76.902 2072 77.028 2073 77.198 2074 77.392 2075 77.604 2076 77.676 2077 77.79 2078 77.932 2079 78.104 2080 78.309 2081 78.374 2082 78.483 2083 78.645 2084 78.855 2085 79.112 2086 79.213 2087 79.377 2088 79.591 2089 79.84 2090 80.139 2091 80.278 2092 80.471 2093 80.72 2094 81.026 2095 81.39 2096 81.559 2097 81.789 2098 82.075 2099 82.405 2100 82.776