Year Number 1950 55.523 1951 55.871 1952 55.88 1953 55.959 1954 56.1 1955 56.206 1956 56.531 1957 56.906 1958 57.249 1959 57.435 1960 57.373 1961 56.937 1962 56.558 1963 56.069 1964 55.327 1965 54.328 1966 53.762 1967 52.813 1968 51.73 1969 50.856 1970 50.351 1971 50.187 1972 50.318 1973 50.643 1974 50.96 1975 51.155 1976 51.412 1977 51.582 1978 51.641 1979 51.559 1980 51.319 1981 51.063 1982 50.607 1983 50.075 1984 49.639 1985 49.391 1986 49.374 1987 49.522 1988 49.751 1989 49.947 1990 50.057 1991 50.313 1992 50.416 1993 50.418 1994 50.4 1995 50.39 1996 50.542 1997 50.937 1998 51.495 1999 52.062 2000 52.524 2001 52.593 2002 52.374 2003 51.912 2004 51.305 2005 50.628 2006 49.816 2007 49.029 2008 48.364 2009 47.938 2010 47.823 2011 47.998 2012 48.378 2013 48.9 2014 49.49 2015 50.111 2016 50.951 2017 51.787 2018 52.593 2019 53.293 2020 53.842 2021 54.389 2022 54.763 2023 55.019 2024 55.229 2025 55.438 2026 55.767 2027 56.086 2028 56.395 2029 56.689 2030 56.969 2031 57.367 2032 57.761 2033 58.145 2034 58.526 2035 58.918 2036 59.456 2037 59.978 2038 60.493 2039 61.009 2040 61.516 2041 62.138 2042 62.766 2043 63.368 2044 63.889 2045 64.296 2046 64.742 2047 65.098 2048 65.405 2049 65.743 2050 66.17 2051 66.792 2052 67.504 2053 68.271 2054 69.02 2055 69.699 2056 70.347 2057 70.93 2058 71.469 2059 72.004 2060 72.559 2061 73.148 2062 73.756 2063 74.365 2064 74.946 2065 75.474 2066 75.967 2067 76.436 2068 76.861 2069 77.207 2070 77.45 2071 77.59 2072 77.664 2073 77.679 2074 77.662 2075 77.644 2076 77.593 2077 77.557 2078 77.555 2079 77.593 2080 77.656 2081 77.667 2082 77.754 2083 77.891 2084 78.05 2085 78.229 2086 78.367 2087 78.551 2088 78.784 2089 79.06 2090 79.363 2091 79.565 2092 79.826 2093 80.127 2094 80.447 2095 80.775 2096 80.968 2097 81.204 2098 81.473 2099 81.757 2100 82.041