Year Number 1950 51.509 1951 52.067 1952 52.079 1953 51.721 1954 51.44 1955 51.536 1956 52.188 1957 53.093 1958 54.175 1959 55.089 1960 55.528 1961 55.657 1962 55.32 1963 54.653 1964 53.987 1965 53.553 1966 52.687 1967 52.526 1968 52.723 1969 52.768 1970 52.454 1971 53.295 1972 53.17 1973 52.663 1974 52.594 1975 53.29 1976 53.802 1977 55.302 1978 57.204 1979 58.508 1980 58.702 1981 58.645 1982 57.458 1983 55.643 1984 54.025 1985 53.024 1986 52.24 1987 52.102 1988 52.304 1989 52.318 1990 51.87 1991 51.959 1992 51.378 1993 50.405 1994 49.511 1995 48.931 1996 48.174 1997 47.939 1998 47.965 1999 47.835 2000 47.371 2001 47.323 2002 46.898 2003 46.233 2004 45.605 2005 45.151 2006 45.004 2007 45.122 2008 45.446 2009 45.865 2010 46.334 2011 46.772 2012 47.184 2013 47.61 2014 48.159 2015 48.886 2016 49.543 2017 50.389 2018 51.341 2019 52.228 2020 52.966 2021 53.764 2022 54.418 2023 54.898 2024 55.181 2025 55.259 2026 55.185 2027 54.886 2028 54.559 2029 54.463 2030 54.752 2031 55.524 2032 56.71 2033 58.159 2034 59.636 2035 61.004 2036 62.406 2037 63.682 2038 64.895 2039 66.158 2040 67.521 2041 69.039 2042 70.629 2043 72.194 2044 73.566 2045 74.635 2046 75.477 2047 76.002 2048 76.328 2049 76.643 2050 77.058 2051 77.62 2052 78.343 2053 79.037 2054 79.449 2055 79.457 2056 79.146 2057 78.438 2058 77.528 2059 76.668 2060 75.969 2061 75.411 2062 75.052 2063 74.819 2064 74.622 2065 74.439 2066 74.431 2067 74.487 2068 74.638 2069 74.903 2070 75.26 2071 75.764 2072 76.423 2073 77.128 2074 77.757 2075 78.262 2076 78.687 2077 78.987 2078 79.224 2079 79.455 2080 79.67 2081 79.771 2082 79.929 2083 80.067 2084 80.132 2085 80.149 2086 80.068 2087 79.955 2088 79.856 2089 79.803 2090 79.782 2091 79.581 2092 79.45 2093 79.37 2094 79.33 2095 79.34 2096 79.249 2097 79.245 2098 79.343 2099 79.531 2100 79.781