Year Number 1950 53.49 1951 53.058 1952 51.913 1953 50.413 1954 49.045 1955 48.153 1956 48.773 1957 49.443 1958 50.334 1959 51.38 1960 52.401 1961 52.644 1962 53.113 1963 53.589 1964 53.762 1965 53.51 1966 53.394 1967 52.788 1968 51.917 1969 51.169 1970 50.737 1971 50.088 1972 49.825 1973 49.826 1974 49.853 1975 49.787 1976 50.114 1977 50.222 1978 50.176 1979 50.077 1980 49.977 1981 49.81 1982 49.666 1983 49.556 1984 49.444 1985 49.313 1986 49.437 1987 49.428 1988 49.351 1989 49.342 1990 49.46 1991 49.708 1992 50.096 1993 50.428 1994 50.401 1995 49.861 1996 49.2 1997 48.04 1998 46.635 1999 45.375 2000 44.481 2001 44.15 2002 44.153 2003 44.31 2004 44.327 2005 44.035 2006 43.768 2007 43.438 2008 43.128 2009 42.855 2010 42.57 2011 42.701 2012 42.547 2013 42.392 2014 42.604 2015 43.336 2016 44.383 2017 46.008 2018 47.892 2019 49.563 2020 50.756 2021 51.839 2022 52.447 2023 52.696 2024 52.847 2025 53.066 2026 53.578 2027 54.085 2028 54.53 2029 54.778 2030 54.743 2031 54.666 2032 54.381 2033 53.973 2034 53.573 2035 53.279 2036 53.34 2037 53.505 2038 53.752 2039 54.052 2040 54.395 2041 55.056 2042 55.731 2043 56.458 2044 57.272 2045 58.169 2046 59.413 2047 60.704 2048 62.012 2049 63.305 2050 64.564 2051 66.055 2052 67.487 2053 68.781 2054 69.813 2055 70.486 2056 71.036 2057 71.245 2058 71.118 2059 70.692 2060 70.017 2061 69.362 2062 68.49 2063 67.438 2064 66.241 2065 64.928 2066 63.765 2067 62.514 2068 61.284 2069 60.221 2070 59.41 2071 59.154 2072 59.136 2073 59.291 2074 59.514 2075 59.731 2076 60.263 2077 60.803 2078 61.341 2079 61.857 2080 62.327 2081 63.006 2082 63.642 2083 64.21 2084 64.685 2085 65.054 2086 65.49 2087 65.832 2088 66.073 2089 66.206 2090 66.228 2091 66.233 2092 66.145 2093 65.97 2094 65.729 2095 65.444 2096 65.184 2097 64.878 2098 64.558 2099 64.262 2100 64.015