Year Number 1950 55.767 1951 55.557 1952 55.529 1953 55.35 1954 55.159 1955 55.216 1956 56.537 1957 57.554 1958 58.584 1959 59.806 1960 61.201 1961 62.577 1962 64.127 1963 65.609 1964 66.641 1965 67.016 1966 66.967 1967 66.355 1968 65.253 1969 63.895 1970 62.46 1971 60.567 1972 59.007 1973 57.735 1974 56.588 1975 55.454 1976 55.046 1977 54.373 1978 53.584 1979 52.948 1980 52.614 1981 52.43 1982 52.492 1983 52.716 1984 52.981 1985 53.26 1986 54.057 1987 54.92 1988 55.715 1989 56.347 1990 56.758 1991 57.166 1992 57.181 1993 56.834 1994 56.196 1995 55.308 1996 54.318 1997 53.25 1998 52.054 1999 50.639 2000 48.982 2001 47.246 2002 45.339 2003 43.362 2004 41.467 2005 39.747 2006 38.817 2007 38.02 2008 37.367 2009 36.821 2010 36.357 2011 35.862 2012 35.341 2013 34.852 2014 34.552 2015 34.574 2016 35.269 2017 36.308 2018 37.538 2019 38.712 2020 39.676 2021 40.534 2022 41.214 2023 41.748 2024 42.219 2025 42.684 2026 43.312 2027 43.899 2028 44.387 2029 44.699 2030 44.792 2031 44.803 2032 44.616 2033 44.321 2034 44.032 2035 43.82 2036 43.796 2037 43.854 2038 43.978 2039 44.155 2040 44.388 2041 44.91 2042 45.481 2043 46.135 2044 46.899 2045 47.763 2046 48.966 2047 50.245 2048 51.647 2049 53.268 2050 55.167 2051 57.581 2052 60.279 2053 63.118 2054 65.835 2055 68.221 2056 70.431 2057 72.278 2058 73.742 2059 74.849 2060 75.627 2061 76.202 2062 76.407 2063 76.297 2064 75.946 2065 75.407 2066 74.848 2067 74.113 2068 73.287 2069 72.481 2070 71.773 2071 71.436 2072 71.199 2073 71.046 2074 70.95 2075 70.893 2076 71.261 2077 71.672 2078 72.103 2079 72.483 2080 72.739 2081 73.25 2082 73.687 2083 74.017 2084 74.215 2085 74.281 2086 74.569 2087 74.757 2088 74.845 2089 74.84 2090 74.747 2091 74.734 2092 74.658 2093 74.513 2094 74.304 2095 74.042 2096 73.811 2097 73.539 2098 73.252 2099 72.977 2100 72.722